Desmodromia McLay, 2001

Guinot, Danièle & Tavares, Marcos, 2003, A new subfamilial arrangement for the Dromiidae de Haan, 1833, with diagnoses and descriptions of new genera and species (Crustacea, Decapoda, Brachyura), Zoosystema 25 (1), pp. 43-129 : 58-64

Genus Desmodromia McLay, 2001

Desmodromia McLay, 2001b: 1-8 .

TYPE SPECIES. — Desmodromia griffini McLay, 2001 by original designation. Gender: feminine.

SPECIES INCLUDED. — Desmodromia griffini McLay, 2001 ; D. tranterae McLay, 2001 .

DISTRIBUTION. — Australia.

DESCRIPTION

See McLay 2001b: 1-8, figs 1-3, table 1.

REMARKS

The inclusion in the Dromiinae n. status of the presumably shell-carrying species of the genus Desmodromia (regarded as an “unusual dromiid crab” by McLay 2001b: 1) is puzzling. The males of both species are unknown and the description of the females is incomplete. Important information on the two small Desmodromia species (not available during this study) is missing, such as: 1) organization of thoracic sternum; 2) shape of male abdomen; 3) male uropods (showing as well-developed dorsal plates in an immature female of D. tranterae ); 4) complete male pleopodal formula; and 5) morphology of male P5 coxa (presence or not of a differentiated mobile penial tube). Besides, it remains unclear whether the last legs are really dissimilar in size and shape (also their terminal grasping apparatus have not been figured in detail) and whether the female thoracic sternites 7 and 8 are tilted. The female sternal sutures 7/8 ending apart between P2 ( McLay 2001b: 2) are typically dromiine.

Despite some resemblance of the short and upturned dactyli of P4 and P5 to that of the shell-carrying Hypoconcha, McLay (2001b: 8) separated Desmodromia in his key from the couplet Conchoecetes / Hypoconcha .

As far as we can tell, Desmodromia and Conchoecetes ( Fig. 3 ) share the following characters: 1) female sternal sutures 7/8 ending between P2; and 2) abdomen hold folded by dorsal uropods and, mostly, by a structure on P2 coxae. Besides their different carapaces, Desmodromia and Conchoecetes differ from each other in: 1) epipod absent on P 1 in Desmodromia (present in Conchoecetes ); 2) P4 and P5 more or less similar, with same dactylus which is simply upturned and without opposing propodal spines (P4 and P5 markedly dissimilar in size and shape in Conchoecetes , with P4 very stout and specialized subcheliform apparatus, P5 filiform and ending in small upturned dactylus; see Guinot & Tavares 2000: fig. 4); and 3) abdominal holding by structure on P2 coxa only (additional efficient structure on P3 coxae and inefficient structure on P4 coxae in Conchoecetes , Fig. 3B ; see Guinot & Bouchard 1998: 622, fig. 4A).

The carapace of Desmodromia , although not membranous on posterior half as in Hypoconcha , may be poorly calcified and flattened, and the eaves overhang eyes. The differences between Desmodromia and Hypoconcha consist of: 1) epipod absent on P 1 in Desmodromia (present in Hypoconcha ); 2) uropods as dorsal plates (as minute ventral plates in Hypoconcha , Fig. 19B, C ); 3) female sternal sutures 7/8 ending between P2 (more posteriorly in Hypoconcha , Fig. 19A ); 4) P2 coxae and uropods functioning in abdominal holding (in Hypoconcha either a differentiation on P1 coxa without involvement of uropods or only provided by strong natural flexion of abdomen, see Guinot & Bouchard 1998: fig. 1C, D); and 5) P4 and P5 simply ending in upturned dactylus (with diverse specialized features in Hypoconcha , see under Hypoconchinae n. subfam., and Guinot & Tavares 2000: fig. 5).

For a comparison of Desmodromia with Epipedodromia ( Fig. 7A ) and Homalodromia ( Fig. 9 ), in which the eyes and cephalic appendages are also ventrally located, see discussion of Homalodromia .

Carrying behaviour

Unknown, but supposedly bivalve shells ( McLay 2001b: 7, 8). For comments on shell-carrying in Dromiidae , see under Discussion, Shell-carrying behaviour.

Genus Dromidia Stimpson, 1858 sensu nobis ( Fig. 5 ) Dromia – Lamarck 1818 pro parte: 264. — Lucas 1840 pro parte: 113. (Non Dromia Weber, 1795 ).

Dromidia Stimpson, 1858 pro parte: 225; 1907 pro parte: 170. — Borradaile 1903a pro parte: 299. — Stebbing 1910 pro parte: 342. — Barnard 1950 pro parte: 319. — Tirmizi & Kazmi 1991 pro parte:27. — McLay 1993 pro parte: 125, 183, table 5. — McLay et al. 2001 pro parte: 740, table 3.

Non Platydromia Brocchi, 1877: 54 (type species: P. depressa Brocchi, 1877 by monotypy).

Non Parasphaerodromia Spiridonov, 1992: 69 (type species: P. subglobosa Spiridonov, 1992 by original designation).

TYPE SPECIES. — Dromia hirsutissima Lamarck, 1818 by original designation ( Stimpson 1858: 225). Gender: feminine.

Lamarck (1818: 264) stated that his Dromia hirsutissima came from Cape of Good Hope (“Cap de Bonne- Espérance”) and that it was deposited in the Paris Museum. H. Milne Edwards (1837: 176 as Dromia hirtissima , sic) seems to have examined the same material and also mentioned that it was housed in the Paris Museum. The only specimen of Dromidia hirsutissima ( Lamarck, 1818) in the MNHN collections is a male (26.6 × 31 mm) labeled “Cap de Bonne-Espérance” ( MNHN-B 22034), and without details on the label. This specimen, presently preserved in alcohol (at one time dry, and perhaps rehydrated), is presumed to be the type of Dromia hirsutissima and is selected here as the lectotype of the species.

SPECIES INCLUDED. — Dromia hirsutissima Lamarck, 1818 .

Whether Dromidia aegibotus Barnard, 1947 , Dromidia dissothrix Barnard, 1947 and Dromidiopsis cornuta Barnard, 1947 belong to Dromidia , as stated by McLay (1993), deserves further investigation. Dromidia spongiosa Stimpson, 1858 is herein transferred to Platydromia Brocchi, 1877 .

DISTRIBUTION. — South Africa.

DESCRIPTION

Carapace wider than long, convex; dorsal surface only with low gibbosities; only branchial groove marked. Anterolateral margin long, with one tooth separated from exorbital angle by a deep concavity, and followed by a prominence; a blunt tooth behind branchial groove; posterolateral margins very short, markedly convergent posteriorly. Front inclined, narrow, with median rostral tooth directed downwards, and two pseudorostral teeth; supraorbital, suborbital and exorbital teeth present. Antenna: basal article with exopod more developed than internal angle which is hardly produced. Mxp3: coxae separated by narrow gap.

Thoracic sternite 3 hardly visible dorsally; sternite 4 forming plate weakly hollowed medially, with lateral borders oblique and anterior margin gently rounded ( Fig. 5A, B ). Female sternal sutures 7/8 long, with apertures of spermathecae ending together on slight prominence between chelipeds. When male abdomen is applied against ventral surface, only a small part of sternite 4 and episternite 4 remaining exposed.

Male abdomen long, wide, with distinct spaced pleural parts, and with all segments free; telson broadly triangular, ending in acute tip ( Fig. 5B, C ). Male segment 6 with external borders parallel. Vestigial pleopods present in males, as elongated lobes on segments 3-5 ( Fig. 5C ). Uropods showing as narrow ventral plates, deeply inserted ventrally, oblique, hardly visible dorsally. Uropods not involved in holding of abdomen. On P2 coxa a strong spine, directed backwards, which may maintain abdominal segment 5 only when P2 are moved backwards.

Chelipeds long, without epipod. P1, P2 and P3 thick, not nodose or ridged; propodus of P2 and P3 without distal spine; inner margin of dactylus armed with spines. P4 and P5 reduced, P5 being more slender. Propodus of P4 and P5 with distal spine opposing dactylus, which is very long and ends in horny spine; a spine on external border of P5 propodus.

Male P5 coxa with mobile penial tube ( Fig. 5A ).

Carrying behaviour

Individuals carry a compound ascidian.

REMARKS

McLay (1993: 183) stressed the confusion regarding the concept of Dromidia , for which “no fewer than eight definitions have been published”. The present new restricted description is based on the type species of the genus, D. hirsutissima , previously poorly known and endemic to South Africa (see Barnard 1950: 320, fig. 61ac). Stimpson (1858: 225) clearly defined the genus by the female sternal sutures 7/8 (“sulci”) ending together between chelipeds, “in tuberculum approximati”. For Rathbun (1923b: 67, 68) the Hawaiian Dromia hirsutissima of Dana (1852) and Edmondson (1922) belong to Dromia dormia ( Linnaeus, 1763) .

The differences that enable to distinguish Dromidia from Austrodromidia ( Figs 1 ; 2 ), both sharing ventral uropods, include: 1) uropods narrow, oblique, deeply inserted but developed and only slightly visible dorsally in Dromidia (very small plates, may be indistinct in Austrodromidia ); 2) vestigial pleopods Pl3-Pl5 present (absent in Austrodromidia ); 3) apertures of spermathecae ending together on slight prominence between P1 (ending wide apart between P 2 in Austrodromidia ); 4) male segment 6 with external borders parallel (anteriorly concave and posteriorly expanded in Austrodromidia ); 5) male telson ending in acute tip, leaving exposed anterior part of sternite 4 and episternite 4 (telson bluntly rounded at tip, almost completely recovering sternite 4, but episternites 4 and 5 exposed, in Austrodromidia ); and 6) abdomen maintained folded by a strong P2 coxal spine, directed backwards (a sharp prominence on P2 coxa in Austrodromidia ).

The presence of uropods is not mentioned by Barnard (1947, 1950) in Dromidia aegibotus and Dromidiopsis cornuta , meaning perhaps that they are ventral. In both species, the apertures of spermathecae end on prominence between P1. In Dromidiopsis aegibotus telson ends in sharp point and P2 coxa bears a sharp spine directed backwards, as in Dromidia hirsutissima . The generic status of these two species and of D. dissothrix , only known by a female, remains uncertain.

Genus Dromidiopsis Borradaile, 1900 sensu nobis ( Fig. 6 )

Dromia – H. Milne Edwards 1837 pro parte: 178. — Haswell 1882a pro parte: 755; 1882b pro parte: 139. (Non Dromia Weber, 1795 ).

Dromidiopsis Borradaile, 1900: 572 ; 1903a: 298; 1903b pro parte: 576. — Holthuis 1962: 56. — Lewinsohn 1984 pro parte: 95, 97-103. — Forest 1974 pro parte: 72, 74, 102, 103. — McLay 1993 pro parte: 135-137, table 2; 2001a pro parte: 79, 80. — McLay et al. 2001 pro parte: 733, 742, tables 2, 3. — Chen & Haibao 2002? pro parte: 102, 541.

TYPE SPECIES. — Dromia australiensis Haswell, 1882 by monotypy and subsequent designation (see Holthuis 1962: 56; McLay 1993: 135, 136, and below). Gender: feminine.

SPECIES INCLUDED. — Dromia australiensis Haswell, 1882 ; Dromidiopsis edwardsi Rathbun, 1919 ; and Dromidiopsis tridentata Borradaile, 1903 . Probably also Sphaerodromia lethrinusae Takeda & Kurata, 1976 included in Dromidiopsis by McLay (1993: 135, 139), see below.

Two species assigned to Dromidiopsis by McLay (1993, 2001), D. globosa ( Lamarck, 1818) and D. dubia Lewinsohn, 1984 , are herein excluded from Dromidiopsis sensu nobis: D. globosa becomes the type species of Lamarckdromia n. gen., while D. dubia is included in Mclaydromia n. gen. The generic status of Dromidiopsis richeri McLay, 2001 remains doubtful.

DISTRIBUTION. — Indo-West Pacific.

DESCRIPTION

Carapace longer than wide, strongly convex; dorsal surface smooth, with regions not defined; branchial groove poorly defined. Anterolateral margin entire or armed with several blunt (variable) teeth; only a small tooth behind branchial groove; posterolateral margin about as long as anterolateral margin. Front appearing almost entire, only bilobed or with two rounded very low pseudorostral teeth; rostrum strongly deflexed, not or hardly visible dorsally; no supraorbital and exorbital teeth; suborbital tooth faintly indicated. Antenna: urinal article thick, slightly wider than long, and with anterior part of beak very narrow; basal article with exopod well-developed and internal corner acutely produced. Mxp3: coxae not completely approximated.

Thoracic sternite 3 very slightly visible. Thoracic sternite 4 narrow, with anterior margin bluntly truncate. Female sternal sutures 7/8 getting progressively close to each other; apertures of spermathecae ending between P1 or just behind them, together on central prominence. When male abdomen is applied against ventral surface, no part or only extreme anterior part of sternite 4, with small episternite 4, remaining visible (setae of telson anteriorly covering sternite 4); episternite 5 not visible.

Male abdomen with segments 5-6 fused (sutures may be partly visible); telson long, ovate and rounded at tip. Male segment 5 with posterior angles expanded; segment 6 with external borders oblique and slightly thickened on edge. No vestigial pleopods in males. Uropods as dorsal plates narrow and oriented vertically in males, as horizontal plates in females. Uropods involved in holding of abdomen, provided by strong dentate crest on coxa of P2; in addition, presence of a granular prominence on P1 coxa, in contact with telson.

Chelipeds with epipod. P2 and P3 short and stout, not knobbed or nodose; propodus of P2 and P3 without distal spine; inner margin of dactylus armed with spines. P4 and P5 reduced, but P5 relatively long and, when extended forward, reaching as far as outer orbital angle. Propodus of P4 only slightly longer than wide. P5 much longer than P4, merus and carpus elongated; propodus, clearly longer than wide, being noticeably longer than that of P4. Subcheliform apparatus formed by one distal spine opposing dactylus; on P5 one outer propodal spine and one outer dactylus spine.

P5 coxa with mobile penial tube.

Male G2 with needle-like flagellum almost reaching anterior margin of sternite 4 and completely covered by abdomen.

Carrying behaviour

Sponges, compound or solitary ascidians.

REMARKS

Dromia australiensis (Haswell, 1882) is the type species of Dromidiopsis ( Borradaile 1900: 572) by monotypy ( Holthuis 1962: 56). However, McLay (1993: 135) indicated Dromia australiensis as type species “by present designation”. On account of the fact that “most records of D. australiensis in the literature are more likely to represent D. tridentata than D. australiensis ”, including those of Borradaile (1900) and Lewinsohn (1984: 100), McLay concluded that “the name of the genus [ Dromidiopsis ], definition of the genus, and description of the type species all occured at different times”. Borradaile (1903a, b) “gave a definition of Dromidiopsis which clearly included D. tridentata but not necessarily Dromia australiensis ” ( McLay 1993: 135, 136), hence the necessity to clearly designate here the type species of Dromidiopsis .

Dromidiopsis australiensis is a poorly known species, only briefly described and not figured by Haswell (1882a: 755; 1882b: 139). Unfortunately, in recent years not enough attention has been paid to this species ( McLay 1993: 136, 137 in key; 2001a: 79, 80 in key). Although Lewinsohn (1984: 99-101, pl. 3, fig. A, pl. 4, figs A, B) compared D. australiensis with D. tridentata and cleared up the synonymy of these two species, many important morphological characters of D. australiensis remained obscure. This situation led McLay (1993: 135, table 2; 2001a: 79) to propose a composite Dromidiopsis . According to McLay (2001: 80, key), the following seven species belong to Dromidiopsis : D. australiensis , D. dubia , D. edwardsi , D. globosa , D. lethrinusae , D. tridentata and D. richeri . Dromidiopsis sensu nobis is herein restricted and now includes only D. australiensis , D. edwardsi and D. tridentata , and perhaps D. lethrinusae . Its main diagnostic features are as follows: 1) front and orbital border entire or without marked teeth; 2) male abdomen with segments 5-6 fused; 3) telson long; 4) male uropods showing as dorsal plates vertically oriented ( Fig. 6B ); and 5) female sternal sutures 7/8 long, and apertures of spermathecae ending between P1 or just behind them, together on central prominence ( Fig. 6A ).

Dromidiopsis edwardsi , a new name given by Rathbun (1919: 197) to the Indo-West Pacific crab identified as “ Dromia caputmortuum ” by H. Milne Edwards (1837: 178, “from Indian Ocean”) (non Cancer caputmortuum Linnaeus, 1766 ), remains in Dromidiopsi s sensu nobis. We examined the material labeled Dromia caputmortuum by H. Milne Edwards (1837), two dry specimens without locality and in poor condition (MNHN-B 1 and 2). These specimens constitute the syntypes of Dromidiopsis edwardsi . Because a holotype has not been designated, the female specimen MNHN-B 2, with the mention “Exp. de l’ Astrolabe ”, is now selected as the lectotype, and the remaining individual is the paralectotype. McLay (1993: 137) remarks that “there is a need to clarify the validity of the records outside Australia ” for D. edwardsi (see Rathbun 1923a: 145). The records from Indian Ocean and Indonesia may belong to another species, perhaps D. tridentata . The sperm of D. edwardsi has been described by Jamieson et al. (1993).

Sphaerodromia lethrinusae Takeda & Kurata, 1976 , described on basis of small specimens, was assigned to Dromidiopsis by McLay (1993: 135, 139) but left in Sphaerodromia Alcock, 1899 by Chen & Haibao (2002: 76, fig. 29). The original immature female was shown with incompletely developed sternal sutures 7/8 ( Takeda & Kurata 1976: fig. 1.4), but mature females examined by McLay (1993: 140) has long sutures 7/8 which end between chelipeds, and also other characters indicating that S. lethrinusae should be placed in Dromidiopsis .

Dromidiopsis globosa and D. dubia should no longer be referred to Dromidiopsis sensu nobis. For D. globosa we establish Lamarckdromia n. gen. ( Fig. 10 ), whose main characteristics are: 1) all abdominal segments free and presence of pleural parts; 2) uropods showing as completely concealed ventral plates; 3) apertures of spermathecae ending between P2; and 4) uropods not used to maintain the abdomen when folded.

Dromidiopsis dubia , also excluded from Dromidiopsis sensu nobis, is herein attributed to Mclaydromia n. gen., whose male uropods show as salient dorsal plates that are obliquely oriented ( Fig. 12A, M . colini n. sp.). A male abdomen with all segments free is another difference between Mclaydromia n. gen. and Dromidiopsis sensu nobis.

The generic status of Dromidiopsis richeri remains uncertain. McLay (2001a: 82, figs 1, 4A) indicat- ed in his key that D. richeri belonged to the third couplet, containing D. globosa . Dromidiopsis richeri is only known from two immature females (perhaps parasitized), in which the apertures of spermathecae lie between P3 (probably more forward in sexually mature females), the uropods (present in the smallest specimen, absent in the largest) show as dorsal plates, vertically oriented, and the abdominal holding is still effective. D. globosa , on the other hand, is the type species of Lamarckdromia n. gen. ( Fig. 10 ), characterized by uropods showing as ventral plates and by anterolateral border of carapace having a single tooth. Dromidiopsis globosa and D. richeri cannot be placed in the same genus.

Dromidiopsis sensu nobis and Lauridromia McLay, 1993 , which consist of large-sized species, share many features: shape of male abdomen (with segments 5 and 6 partly fused), uropods narrow and vertically oriented, holding prominences on P2 and also on P1 coxae, and sternal sutures 7/8 ending at level of the chelipeds. The differences between Dromidiopsis and Lauridromia are very few (see McLay 1993: 135, 145, table 2): small size of individuals in Dromidiopsis (large size in Lauridromia ); apertures of spermathecae located together on central prominence ( Fig. 6A ) (wide apart on long and strong tubercles in typical Lauridromia ). In L. indica (Gray, 1831) , however, the female sternal sutures 7/8 end together at summit of two coalescent tubercles; in these respects, L. indica seems to be close to Dromidiopsis .

Figures

FIG. 3. — A, Conchoecetes artificiosus (Fabricius, 1798), Madagascar, Nosy-Bé, 23 × 22 mm (MNHN-B 6890), thoracic sternum, two front views, and spermathecae; B, C, Conchoecetes intermedius Lewinsohn, 1984; B, Madagascar, 16 × 17 mm, holotype (MNHN-B 6891), thoracic sternum with abdomen; C, Moluccas, 9 × 9 mm (MNHN-B 15890), abdomen, ventral view; note absence of vestigial pleopods. Abbreviations: a3-a6, abdominal segments 3-6; cx1-cx5, coxae of P1-P5; e4, e5, episternites 4, 5; mxp3, external maxilliped (coxae separated for clarity); n, notch on margin of abdominal segment 5; o, female gonopore; pr, holding prominence; s, aperture of spermatheca; sp, sperm plug; t, telson; u, uropod; 1-2, sternites 1-2 (normally covered by mxp3 coxae, closely approximated); 3-8, sternites 3-8; 4/5-7/8, thoracic sternal sutures 4/5-7/8. Dotted line indicates difference in level. Scale bars: 1 mm.

FIG. 19. — A, B, Hypoconcha californiensis Bouvier, 1898, Gulf of California, San José Island (MNHN-B 22066); A, 17 × 18 mm, syntype, thoracic sternum, two front views; note sternites 7 and 8 strongly tilted and perpendicular to preceding ones; B, 20.3 × 19.4 mm, syntype, ventral view of abdomen, with asymmetrical, uniramous vestigial pleopods and uropods showing as ventral plates; C, H. panamensis Smith, 1869, Lower California, Bouvier det. H. digueti Bouvier, 1898, Diguet coll., about 32 mm width (MNHN-B 22071), abdomen, ventral view; note uropods showing as setiferous ventral lobes. Abbreviations: a3-a6, abdominal segments 3-6; cx1-cx5, coxae of P1-P5; e4, e5, episternites 4, 5; mxp3, external maxilliped; o, female gonopore; pl, female pleopod (setae incompletely figured); s, aperture of spermatheca; t, telson; u, uropod; v3-v5, vestigial pleopods 3-5; 3-8, sternites 3-8; 4/5-7/8, thoracic sternal sutures 4/5-7/8. Dotted line indicates difference in level. Scale bars: A, C, 2.5 mm; B, 1mm.

FIG. 7. — A, Epipedodromia thomsoni (Fulton & Grant,1902),Australia,Victoria, Port Phillip, 9 × 11 mm (BM 1884-39), thoracic sternum and spermathecae; B, Hemisphaerodromia monodus (Stebbing, 1918), Madagascar, Fort-Dauphin,Decary coll., det.H. abellana Barnard, 1954, 16 × 18 mm (MNHN-B 12725), thoracic sternum and spermathecae.Abbreviations: cx1-cx5, coxae of P1-P5; e4, e5, episternites 4, 5; mxp3, external maxilliped; o, female gonopore; r, medial ridge; s, aperture of spermatheca; 1-3, sternites 1-3; 4-8, sternites 4-8; 4/5-7/8, thoracic sternal sutures 4/5-7/8. Dotted line indicates difference in level.Scale bars: 2.5 mm.

FIG. 9. — A, Homalodromia coppingeri Miers, 1884, Seychelles, 5.2 × 5.3 mm (MNHN-B 26130), thoracic sternum with abdomen; B, Homalodromia? coppingeri Miers, 1894, New Caledonia, LAGON, stn 556, 7.8 × 9 mm (MNHN-B 22528), thoracic sternum and spermathecae; note apertures of spermathecae at level of P1, concealed by sperm plug, and vestigial holding prominence on P2 coxa of female. Abbreviations: a6, abdominal segment 6; b, tubular bridge between apertures of spermathecae; cx1-cx4, coxae of P1-P4; e4, episternite 4; mxp3, external maxilliped; o, female gonopore; pr, holding prominence; sp, sperm plug; t, telson; u, uropod; v, vestige of the holding prominence in the female; 4-8, sternites 4-8; 4/5-7/8, thoracic sternal sutures 4/5-7/8. Scale bar: 1 mm.

FIG. 5. — Dromidia hirsutissima (Lamarck, 1818), “Cap de Bonne-Espérance”, 26.6 × 31 mm, lectotype (MNHN-B 22034); A, thoracic sternum, two front views; B, C, abdomen, dorsal and ventral views; note uropods showing as ventral plates, hardly visible dorsally. Abbreviations: a5, a6, abdominal segments 5, 6; cx1-cx5, coxae of P1-P5; e4, e5, episternites 4, 5; pr, spiniform holding prominence; pt, penial tube; v4, v5, elongated vestigial pleopods 4 and 5 (pleopods present also on segment 3); t, telson; u, uropod; 4-6, sternites 4-6; 5/6-7/8, thoracic sternal sutures 5/6-7/8. Dotted line indicates difference in level. Scale bars: 2 mm.

FIG. 1. — Austrodromidia australis (Rathbun, 1923), New South Wales, off Eden, Goonambee, 1922, 29.5 × 33 mm (AM P5777); A, thoracic sternum, two front views; B, abdomen, dorsal view; C, abdomen, ventral view; note uropods showing as very narrow ventral plates. Abbreviations: a6, abdominal segment 6; cx1-cx5, coxae of P1-P5; e4, e5, épisternites 4, 5; mxp3, external maxilliped; pr, holding prominence; pt, penial tube; t, telson; u, uropod; 1-2, sternites 1-2; 3-8, sternites 3-8; 4/5-7/8, thoracic sternal sutures 4/5-7/8. Dotted line indicates difference in level. Scale bar: 5 mm.

FIG. 2. — Austrodromidia octodentata (Haswell, 1882), South Australia, Kangaroo Island, Endeavour, Rathbun det. Cryptodromia octodentata; A, B, 39 × 42 mm (AM E. 801); A, thoracic sternum, two front views; B, abdomen, ventral view; note uropods reduced to nearly obsolete buds; C, 44 × 46 mm (AM P. P2311), thoracic sternum and apertures of spermathecae, covered with spermatic plug. Abbreviations: a6, abdominal segment 6; cx1-cx5, coxae of P1-P5; e4, e5, episternites 4, 5; mxp3, external maxilliped; o, female gonopore; pr, holding prominence; pt, penial tube; sp, spermatic plug; t, telson; u, uropod; 1-2, sternites 1-2; 3-8, sternites 3-8; 4/5-7/8, thoracic sternal sutures 4/5-7/8. Dotted line indicates difference in level. Scale bars: 5 mm.

FIG. 6. — A, Dromidiopsis tridentata Borradaile, 1903, New Caledonia, LAGON, stn DW 554, ovigerous 12.7 × 12 mm (MNHN-B 22550), thoracic sternum and spermathecae; B, D. australiensis (Haswell, 1882), Australia, Queensland, Cape Bedford, D. J. G. Griffin det., 15.4 × 14 mm (AM P16598), thoracic sternum with abdomen. Abbreviations: a5, a6, abdominal segments 5, 6; cx1- cx5, coxae of P1-P5; e4, episternite 4; mxp3, external maxilliped; o, female gonopore; pr, holding prominence; s, aperture of spermatheca; t, telson (setae covering sternite 4 not shown); u, uropod; 4-8, sternites 4-8; 4/5-7/8, thoracic sternal sutures 4/5-7/8. Dotted line indicates difference in level. Scale bars: 2 mm.

FIG. 10. — Lamarckdromia globosa (Lamarck, 1818) n. comb., New South Wales, Port Jackson, det. Dromidia excavata Stimpson, McLay redet. Dromidiopsis globosa (MNHN-B 22041); A, 25 × 25 mm, thoracic sternum and spermathecae; B-D, 24 × 25 mm, extremity of abdomen in dorsal view, abdomen in ventral view, and thoracic sternum without abdomen. Abbreviations: a3, a6, abdominal segments 3, 6; cx1-cx5, coxae of P1-P5; e4, e5, episternites 4, 5; mxp3, external maxilliped; o, female gonopore; pr, holding prominence; pt, penial tube; s, aperture of spermatheca; t, telson; u, uropod; 1-2, sternites 1-2; 3-8, sternites 3-8; 4/5-7/8, thoracic sternal sutures 4/5-7/8. Dotted line indicates difference in level. Scale bars: 2.5 mm.

FIG. 12. — Mclaydromia colini n. gen., n. sp.; A, LAGON, stn 111, 25 m, 10.4 × 9.1 mm, paratype (MNHN-B 26282), thoracic sternum with abdomen; B, LAGON, stn 569, 62 m, ovigerous 9.4 × 8.6 mm, paratype (MNHN-B 26289), thoracic sternum and spermathecae. Abbreviations: a6, abdominal segment 6; cx1-cx4, coxae of P1-P4; e4, episternite 4 (very small); mxp3, external maxilliped (coxae separated for clarity); o, female gonopore; pr, holding prominence; s, aperture of spermatheca; t, telson; u, uropod; 1-2 sternites 1-2 (normally not exposed); 3, sternite 3; 4-8, sternites 4-8; 4/5-7/8, thoracic sternal sutures 4/5-7/8. Dotted line indicates difference in level. Scale bars: 2.5 mm.