Demanietta sirikit Naiyanetr, 1992

Brandis, Dirk, 2002, On the taxonomic status and biogeography of the Isolapotamidae Bott, 1970 (Decapoda, Brachyura), Journal of Natural History 36 (11), pp. 1291-1339 : 1308-1309

Demanietta sirikit Naiyanetr, 1992

(gure 8a–c)

Demanietta sirikit Naiyanetr, 1992a: 113 , pl. 1, gure 1.

Thaiphusa sirikit: Ng and Naiyanter, 1993: 32 , gures 22, 56 [type species of Thaiphusa ].

Taxonomy and biogeography of the family Isolapotamidae 1309

HOLOTYPE. ( RMNHD 38758 ) Amphoe Sai Yok , Mountain creek in Ban Nam Chon: 14ss06¾ 00 ² N 99ss23¾ 00 ² E; leg S. Duangkhahae.

PARATYPES. One, one: SMF 22111, Thailand, Kanchanaburi province, Sai Yok district, Mountain creek in Ban Nam Chon : 14ss06¾ 00 ² N 99ss23¾ 00 ² E; leg S. Duangkhahae .

Diagnosis. Carapace smooth, anterolateral margin well developed, forming one sharp ridge with the postorbital and postfrontal lobes; lateral parts of ridge distinctly rounded, epibranchial teeth lacking; epigastrical groove half circled, chelae of male very unequal, cutting edges forming round, broad gap when closed. Pleon triangular. Terminal joint of rst gonopod slightly S-shaped, distal tip short; overlapping margin reaches dorsal side, only minutely projecting, margins appearing swollen; exible zone narrow, minutely bilobed.

Type locality. Ban Nam Chon, Sai Yok District, Kanchanaburi Province, Thailand.

Distribution. South Thailand.

Measurements. 33: 47.7: 23.8: 11.3 (holotype).

Remarks. The species can be characterized distinctly by the morphology of the rst gonopod as well as by carapace features. The mesial projection of the terminal joint is very low, while the carapace is convex and very smooth. According to Naiyanetr (1992b) D. sirikit is a true land crab. As discussed above, most of the other known species of the genus Demanietta are aquatic and therefore, this species shows some diOEerences in carapace and maxilliped shape.

Flabellamon Ng, 1996 (gures 4b, 9–13) Flabellamon Ng, 1996: 1005 .

Type species. Flabellamon pretzmanni Ng, 1996 [by original designation].

Diagnosis. Terminal joint of rst gonopod with either mesially swollen or largely projecting outer overlapping margin. Terminal part of second gonopod dorsoventrally attened, fused zone of terminal tube of second gonopod turning one and a half times round axis of terminal tube; exible zone short; terminal tube ending in distinct minutely curved tip.

Distribution. Both sides of the Tenasserim range, Kanchanaburi province, central Thailand.

Remarks. The genus was established by Ng (1996) for F. pretzmanni and was originally monotypic. The examination of the second gonopod of material from the Natural History Museum Basel, cited by Ng as F. pretzmanni , shows a very characteristic second gonopod morphology with the contact zone of the tubular edges turning around the longitudinal axis of the second gonopod. Additionally, the terminal joint of the rst gonopod bears at least a small protrusion or swelling in all species examined, which in F. pretzmanni is enlarged to a broad projection. Comparison of Flabellamon with other species from Burma and western Thailand (such as Potamon turgidulimana Alcock, 1910 ; P. pruinosum Alcock, 1909 ; P. kanchanaburiens e Naiyanetr, 1992; or P. erewanense Naiyanetr, 1992 ) showed a general agreement of the second gonopod morphology between these species. It is possible that many more species belong to this genus than was previously thought. The cross-sections of the second gonopod of Flabellamon show agreement with that of Isolapotamon so this genus is included in the Isolapotamidae . The problematic status of the type species, F. pretzmanni , is described below.