Parachondria (Chondropomorus) samanicolus ( Bartsch, 1946 )

Watters, G. Thomas, 2016, Review of the Hispaniolan Parachondria (Chondropomorus) complex (Gastropoda: Littorinoidea: Annulariidae), Zootaxa 4127 (2), pp. 245-275 : 263-264

Parachondria (Chondropomorus) samanicolus ( Bartsch, 1946)

Figures 3 P–W, 6 A

Type material. Chondropoma hemiotum Pfeiffer, 1852a : not located. Pfeiffer, 1852a, refered to “Coll. Nr. 211.” Incertipoma samanicolum Bartsch, 1946: NMNH 369105, holotype.

Type locality. Chondropoma hemiotum Pfeiffer, 1852a : “ Habitat in insula Haiti.” Bartsch (1946) commented that Pfeiffer’s type was collected at Yaque but it is not clear how he knew this; Pfeiffer only gave “ Haiti ” as the type locality. Yaque could refer to several different widely separated places in the Dominican Republic and it is not clear to which Yaque Bartsch was referring. Incertipoma samanicolum Bartsch, 1946: “Boca del Infierno, Dominican Republic.” Bartsch (1946) recorded numerous taxa from this location. Based on other evidence in his paper this is not the town of that name in central Hato Major Province but a sea-side cave on Samaná Bay in that province near San Lorenzo Bay.

Figured type. Chondropoma hemiotum Pfeiffer, 1852a : Pfeiffer, 1854b: pl. 48, figs. 3, 4. Incertipoma samanicolum Bartsch, 1946: Bartsch, 1946, pl. 31, fig. 4.

Cresonymy.? Chondropoma hemiotum Pfeiffer, 1852a: 288 ; Adams & Adams, 1856: 295; Bland, 1861: 355; Reeve, 1863: pl. 3, fig. 18; Pfeiffer, 1865: 152; Pfeiffer, 1876: 194; Kobelt, 1880: 277; Crosse, 1891: 173; Watters, 2006: 290.

? Cyclostoma hemioto [sic] Pfeiffer, 1852. Shuttleworth, 1854: 92.

? Cyclostoma (Chondropoma) hemiotum (Pfeiffer, 1852). Pfeiffer, 1854d: 143.

? Cyclostoma hemiotum (Pfeiffer, 1852) . Pfeiffer, 1854b: pl. 48, figs. 3, 4; Pfeiffer, 1854c: 370 –371; Pfeiffer, 1859: 75.

Incertipoma samanicolum Bartsch, 1946: 178–179. pl. 31, fig. 4; Ruhoff, 1973: 123; Watters, 2006: 460.

Diplopoma (Troschelvindex) ? samanicolum ( Bartsch, 1946). Watters, 2006: 36, 460.

? Parachondria (Parachondria) hemiotus ( Pfeiffer, 1852b). Watters, 2006: 46, 290.

non Chondropoma (Chondropomorus) hemiotum (Pfeiffer, 1852). Henderson & Bartsch, 1920: 61; Bartsch, 1946: 10 –11, pl. 1, fig. 1 [both = C. pilsbryi Bartsch, 1946 ].

Distribution and habitat. Eastern end of the Cordillera Septentrional and the northern Cordillera Oriental in the Río Yuna valley and its tributaries, also east to the southern coast of Samaná Bay; in at least Duarte, Hato Major, and Monte Plata provinces. Under cobble and debris in karst areas of mesic forest on limestone knolls and ledges; some localities cut over for coffee groves. Mostly in the Los Haitises Limestone. A portion of the range is in the Reserva Científica Loma Quita Espuela. Locally common.

Material examined (185 specimens). Dominican Republic. UF 216744(3), 900 m, Loma Quita Espuela, Duarte Province; UF 216418(35), 200 m, 1 km W of Majagual, Monte Plata Province; UF 216478(12), 150 m, 2 km N Majagual, Monte Plata Province; UF 216516(27), 150 m, 5 km N of Majagual, Duarte Province; UF 216407(10), 5 km N of Majagual, Duarte Province; UF 216393(3), 105 m, 7 km N of Majagual, Duarte Province; UF 216515(19), 75 m, 9 km N of Majagual, Duarte Province; UF 216500(16), 20 m, 1 km NW of Arenoso, Duarte Province; UF 216616(49), 9.3 km ENE of Cervicos, Duarte Province; UF 216626(10), 60 m, Batero, Sánchez Ramirez Province; UF 216625(1), 8 km W of Sabana de la Mar, Samaná Province.

Redescription. Shell thin, almost translucent, elongate conic. Maximum adult size: 21.0 mm, decollate. Minimum adult size: 14.2 mm, decollate. Adult shell usually decollated, protoconch of 1.5 minute, smooth whorls, white or tan, demarcation between protoconch and teleoconch not well-defined. Teleoconch of 5 whorls. Axial sculpture of final whorl of numerous (170–200) very fine, narrowly spaced, flattened threads. Shell with regularly spaced growth stoppage marks, axial threads preceding marks microscopic and densely packed. Spiral sculpture of final whorl outside of umbilicus apparent only as minute pustules on axial threads; often lacking entirely on anterior third of whorl. Surface may have frosted appearance. Umbilicus bounded by two weak cords, smooth within. Suture narrow, bounded by small, regularly spaced tufts composed of 1–3 enlarged axial threads. Aperture teardrop-shaped, lip double, rarely single. Inner lip erect but barely exserted. Outer lip expanded, narrower facing umbilicus, slightly recurved abaperturally, adnate with previous whorl or less commonly narrowly solute. Prominent posterior auricle. Smaller, somewhat undulating auricle also present at 8 o’clock position. Color pattern complex and variable. Base color white, tan, pinkish, reddish. Dark marks or band (rarely) below suture; often with brown dots, chevrons, or scribbles on center of whorl; anterior half with broken brown bands or dots; dark brown axial markings at preceding edge of growth marks. Inner lip and both sides of outer lip with dark brown markings. Tufts white. Operculum corneous, paucispiral, lacking calcification.

Variation in specimens. Specimens vary in the degree of coloration. All specimens seen have a row of brown marks below the suture; these vary from small dots to more extensive comma-shaped markings. Adult shells vary greatly in size.

Comparison with other species. This northern species differs from the others reviewed here in having regularly and densely spaced sutural tufts that give a beaded appearance to the suture. It is usually a darkly colored shell but pale specimens superficially resemble P. daedalus and P. isabellinus , which occur on the southern coast.

Remarks. Bartsch’s description and figure of his “ Chondropoma hemiotum ” do not match Pfeiffer’s description or figures. Among other characteristics, Bartsch’s specimen differs from that of Pfeiffer’s in having a solute outer lip and finer sutural cusps. Bartsch’s shell, from an unknown location, is a specimen of P. pilsbryi .

Of the species covered here, Pfeiffer’s species most closely resembles P. samanicolus . As such Pfeiffer’s name would predate Bartsch’s by 94 years. However, Pfeiffer’s description and figures are sufficiently vague that the possibility exists that they may still constitute two different species, with Pfeiffer’s perhaps awaiting rediscovery. Until Pfeiffer’s type is located, or a more likely candidate is uncovered, I have continued the use of Bartsch’s name and regard Pfeiffer’s name as a nomen dubium.

Bartsch (1946) described this species under his “genus” Incertipoma, which he used for species he could not assign to any genus. As pointed out by Watters (2006), Bartsch’s statement (1946: 171) that “the name is used in lieu of a generic name,” clearly indicates that he did not treat the name as valid when proposed. Neither was it a conditional name. Therefore, it did not fulfill the criteria of availability (ICZN Art. 11.5). Although many of the species in this “genus” existed without a valid generic name until Watters (2006) reassigned them, they were nevertheless available species names (ICZN Art. 11.9.3.2). Bartsch had first created this type of “pseudogeneric term” in his review of the Poteriidae and Megalomastomatidae ( Torre et al., 1942) , assigning his problem taxa to Incerticyclas.

Bartsch (1946) did not state why he was reluctant to place this species in an existing genus, but in other places he hesitated due to the lack of an operculum. Watters (2006) placed this species in Diplopoma , with question, also not having seen an operculum. Material presented here, with opercula, allow this species to be properly assigned to Parachondria .

Original descriptions. Chondropoma hemiotum Pfeiffer, 1852a : Pfeiffer (1852a: 288) (translated here from Latin): “Shell perforate, oblong-turret, a little thin, obsolete raised spiral lines, and longitudinally very dense (10– 12 together in bundles) smoothly clathrate, not shining, brownish-white, mostly with red interrupted lines and colored with one wide red band below the middle; spire subtruncate; suture with dense denticles; remaining 5–7 whorls a little convex, last shortly solute in front, dorsum carinate; aperture subvertical, ovale; peristome subduplicate: inner continuous, a little expanded, outer with middle left margin descending, briefly attached, middle right margin terminating in slightly undulating auricle.—Operculum normal.”

Incertipoma samanicolum Bartsch, 1946: see Bartsch (1946: 178–179).

Etymology. Chondropoma hemiotum Pfeiffer, 1852a : unclear, perhaps a version of hemiotis, half-eared, in reference to the auriculate outer lip. Incertipoma samanicolum Bartsch, 1946: dwelling on the Samaná Peninsula.

Figures

FIGURE 3. A – G. Parachondria (Chondropomorus) daedalus new species. A, B. UF 216481, holotype, 15.6 mm. C. UF 216481, paratype 2, 16.4 mm. D. UF 23177, 17.5 mm, note web in umbilicus. E. UF 216481, paratype 1, 13.0 mm. F. UF 216481, holotype, detail of spire. G. UF 216481, holotype, detail of suture.