Parachondria (Chondropomorus) gnotus ( Pilsbry, 1935 )

Watters, G. Thomas, 2016, Review of the Hispaniolan Parachondria (Chondropomorus) complex (Gastropoda: Littorinoidea: Annulariidae), Zootaxa 4127 (2), pp. 245-275 : 253-254

Parachondria (Chondropomorus) gnotus ( Pilsbry, 1935)

Figures 2 A–H , 5 A

Type material. Chondropoma soror Pilsbry, 1933 : ANSP 44344a, holotype; ANSP 374552(9), paratypes [ Chondropoma gnote Pilsbry, 1935 , is a replacement name]. Chondropoma gnote kriegeri Bartsch, 1946 : NMNH 471997, holotype.

Type locality. Chondropoma soror Pilsbry, 1933 : “San Lorenzo, on the south side of Samana Bay, Santo Domingo.” Chondropoma gnote kriegeri Bartsch, 1946 : “archeological village site of the Irawak Indians at the mouth of the San Juan River, which is on the north side of the Samana Peninsula in the Dominican Republic.”

Type figured. Chondropoma soror Pilsbry, 1933 : Pilsbry, 1933, pl. 6, fig. 15, not fig. 14 as stated. The caption to this plate was corrected in Clench & Aguayo (1937): figure “14” is 15; “15–19” is 14, 16–19. Chondropoma gnote kriegeri Bartsch, 1946 : Bartsch, 1946, pl. 2, fig. 8.

Cresonymy. Chondropoma soror Pilsbry, 1933: 124 , pl. 6, fig. 15 [non Chondropoma soror Pilsbry, 1930 ]; Clench & Aguayo, 1937: 65; Bartsch, 1946: 17 [in synonymy of Chondropoma gnote Pilsbry, 1935 ]; Watters, 2006: 274, 489.

Chondropoma gnote Pilsbry, 1935: 144 [new name for Chondropoma soror Pilsbry, 1933 , non Pilsbry, 1930]; Baker, 1964: 170.

Chondropoma (Chondropomorus) gnote gnote Pilsbry, 1935 . Clench & Aguayo, 1937: 65; Bartsch, 1946: 15, 17, pl. 2, fig. 9; Watters, 2006: 273 –274.

Chondropoma (Chondropomorus) gnote kriegeri Bartsch, 1946: 16 , pl. 2, fig. 8; Ruhoff, 1973: 87; Watters, 2006: 274.

Parachondria (Parachondria) gnote gnote ( Pilsbry, 1935) . Watters, 2006: 46, 273–274.

Parachondria (Parachondria) gnote kriegeri ( Bartsch, 1946) . Watters, 2006: 46, 274.

Distribution and habitat. Originally reported from the south shore of Samaná Bay, this species also occurs inland at least 20 km south. It may live on the Samaná Peninsula in general including the north coast. Under rocks and ledges and around chimneys in mesic, forested karst landscape in the Los Haitises Limestone and on the Samaná Peninsula; portions cleared for pastures.

Material examined (48 specimens). Dominican Republic. UF 216392(6), UF 216622(3), 230 m, 7 km NNW of Hato Major del Rey, Hato Major Province; UF 216623(20), 180 m, 6 km NNW of Hato Major del Rey, Hato Major Province; UF 216404(13), 12 km W of Sabana de la Mar, Hato Major Province; UF 216637(6), 50 m, 1 km E of Sánchez, Samaná Province.

Redescription. Shell solid, opaque, high-spired, elongate conic. Maximum adult size: 16.7 mm, decollate. Minimum adult size: 13.5 mm, decollate. Adult shell usually decollated, protoconch of 1.5 minute, smooth whorls, white or tan, demarcation between protoconch and teleoconch well-defined. Teleoconch of 6 whorls but typically only 5 remain in decollated shells. Axial sculpture of final whorl of numerous (ca. 120) very fine, narrowly spaced, flattened threads. Shell with regularly spaced growth stoppage marks, axial threads preceding marks often microscopic and densely packed. Spiral sculpture of final whorl outside of umbilicus of 20–30 irregularly sized threads perhaps twice as wide as axial threads. Overall sculpture not distinct giving surface a smudged but microscopically fenestrate appearance. Umbilicus bounded by one or rarely two distinct cords, smooth within. Suture not channeled. Tufts composed of 1–3 only slightly enlarged axial threads that occur just preceding each growth mark. Aperture teardrop-shaped, lip double, rarely single. Inner lip weak, barely exserted, fused to outer lip. Outer lip evenly expanded, except much narrower facing the umbilicus, slightly recurved abaperturally; adnate with previous whorl. Posterior auricle rarely present. Smaller, somewhat undulating auricle rarely present at 8 o’clock position. Color pattern complex and variable. Base color white or tan. Smudged tan axial zig-zags or dots that continue as brown bands on both sides of outer and inner lips. At least one continuous brown band bounding umbilicus. Tufts white. “Operculum thin, corneous, paucispiral” fide Bartsch (1946: 15); lacking in all specimens examined here.

Variation in specimens. Specimens differ in the degree of coloration, but are otherwise quite consistent in terms of sculpture and overall shell form. The range in adult sizes is not as great as that seen in similar species.

Comparison with other species. This species is similar to other high-spired taxa such as P. petitianus , P. trachydermus , and P. silvaticus from which it differs in having smoother sculpture and much less developed tufts.

Remarks. Pilsbry (1935) renamed his 1933 C. soror as C. gnote , having already used the C. soror combination in 1930 for a different species. Bartsch (1946) divided C. gnote into four subspecies, two associated with the Samaná Peninsula area, and two in northwestern Haiti nearly 300 km away. These two groups are here considered two separate species: P. hispaniolae Clench & Aguayo, 1937 ) from Haiti, and P. gnotus ( Pilsbry, 1935) from the Samaná Peninsula area. Chondropoma gnote kriegeri was differentiated from C. gnote s.s. by its more pronounced tufts and paler coloration–differences that exist within individual populations.

Original description. Chondropoma soror Pilsbry, 1933 . Pilsbry (1933: 124): “Shell similar to C. petitianum (Pfr.) , but the sculpture is much weaker; subsutural dentition obsolete, though weak traces of nodes may be seen on the spire.”

Original description. Chondropoma (Chondropomorus) gnote kriegeri Bartsch, 1946 . Bartsch (1946: 16): “It is a pale race beautifully regularly spotted by interrupted spiral bands of brown, which are few in number and distantly spaced axially. The spots here all tend far more toward an axial arrangement than in Chondropoma (Chondropomorus) gnote gnote . Here, too, the tufting at the summit is much more pronounced.”

Etymology. Chondropoma soror Pilsbry, 1933 : L. soror , sister. Chondropoma gnote Pilsbry, 1935 : L. gnotus , recognized [perhaps because he did not recognize his own earlier name “ soror ”]. Chondropoma (Chondropomorus) gnote kriegeri Bartsch, 1946 : Herbert William Krieger (1889–1970), Curator, Division of Ethnology, US National Museum, collector of the types.

Figures

FIGURE 2. A – H. Parachondria (Chondropomorus) gnotus (Pilsbry, 1935). A. Chondropoma soror Pilsbry, 1933, holotype, ANSP 44344 a, ca. 13.5 mm. B. Chondropoma gnote kriegeri Bartsch, 1946: NMNH 471997, holotype, 13.5 mm. C, D. UF 216404, 13.5 mm. E. UF 216404, 12.8 mm. F. UF 216392, 15.1 mm. G. UF 216404, detail of spire. H. UF 216404, detail of suture.