Parachondria (Chondropomorus) heatheraikenae, Watters, G. Thomas, 2016

Watters, G. Thomas, 2016, Review of the Hispaniolan Parachondria (Chondropomorus) complex (Gastropoda: Littorinoidea: Annulariidae), Zootaxa 4127 (2), pp. 245-275 : 254-256

Parachondria (Chondropomorus) heatheraikenae new species

Figures 2 I–O, 6 A

Type material. OSUM 40166, holotype, 13.6 mm; UF 687683, paratype 1, 14.3 mm; UF 78 423, paratype 2, 12.3 mm; BMSM 8236, paratype 3, 11.8 mm.

Type locality. 1290 m elevation, abandoned quarry near end of road between Cabo Rojo and Las Mercedes, Pedernales Province, Dominican Republic. 18.1214 N, - 71.5699 W.

Distribution and habitat. Known only from the type locality on the southern slope of the Sierra de Baoruco. Found under piles of fossil coralline rubble.

Material examined (36 specimens). Dominican Republic. Aiken coll.(31); GTW 16156a(1). All from type locality.

Description. Shell small, solid, opaque, high-spired conic. Maximum adult size: 14.3 mm, non-decollate. Minimum adult size: 11.7 mm, decollate. Adult shell typically decollated, protoconch of 1.5 prominent, smooth whorls, white with dark brown suture at apex and brown band at periphery, demarcation between protoconch and teleoconch not well-defined. Teleoconch of 6 whorls, but only 5 typically retained in decollate specimens. Axial sculpture of final whorl of numerous (70–90) very fine, rounded threads separated by spaces greater than width of threads; threads mostly of uniform size. Shell with regularly spaced growth stoppage marks. Spiral sculpture of final whorl outside of umbilicus of 30–35 rounded threads, same width as axial threads, becoming much finer and more closely set on base. Intersections of axial and spiral sculpture form minutely but distinctly fenestrated surface with plastic appearance. Umbilicus very narrow, bounded by single, weak cord. Suture narrow, largely obscured by sutural tufts. Tufts composed of 1–3 prominent, regularly disposed, fused axial threads that extend onto previous whorl. Aperture oval, lip double. Inner lip tightly adherent to outer lip. Outer lip very narrowly expanded, slightly narrower facing umbilicus, adnate with previous whorl. Posterior edge with wide angle forming weak auricle. Outer lip nearly covers umbilicus. Color pattern complex and variable. Base color white or buff. 4–6 very narrow, spiral brown bands between suture and base, often axially aligned on growth marks as dashes or dots, anterior-most band most prominent and nearly continuous. 1–4 much narrower brown bands continue on base to umbilicus. Umbilicus without markings. Both sides of outer lip with dark brown markings, most prominent anteriorly. Interior of peristome orangish to dark brown. Tufts white. Operculum corneous, paucispiral, lacking calcification.

I–G. Parachondria (Chondropomorus) heatheraikenae new species. I, J. OSUM 40166, holotype, 13.6 mm. K. UF 687683, paratype 1, 14.3 mm. L. UF 78423, paratype 2, 12.3 mm. M. BMSM 8236, paratype 3, 11.8 mm. N. OSUM 40166, holotype, detail of spire. O. OSUM 40166, holotype, detail of suture.

P–V. Parachondria (Chondropomorus) petitianus ( Pfeiffer, 1850) . P. Cyclostoma petitianum Pfeiffer, 1850 , NHMUK 42/10, probable syntype, 13 mm. Q, R. UF 23215, 15.2 mm. S, T. UF 216420, 14.5 mm. U. UF 216420, detail of spire. V. UF 216420, detail of suture.

W–AB. Parachondria (Chondropomorus) silvaticus new species. W, X. UF 216479, holotype, 12.1 mm. Y, Z. UF 216479, paratype 1, 10.0 mm. AA. UF 216479, holotype, detail of spire. AB. UF 216479, holotype, detail of suture. AC–AI. Parachondria (Chondropomorus) trachydermus ( Pilsbry, 1933) . AC. Chondropoma trachyderma Pilsbry, 1933 : ANSP 7872a, holotype, 12 mm. AD. Chondropoma petitianum dominicum Bartsch, 1946 : NMNH 493309, holotype, 12.0 mm. AE, AF. GTW 7072d, 13.7 mm. E. GTW 7072d, 11.9 mm. AG. OSUM 6755, 14.9 mm. AH. GTW 7072d, detail of spire. AI. GTW 7072d, detail of suture.

Variation in specimens. Specimens vary in base coloration from white to dark brown but all have the narrow interrupted brown bands.

Comparison with other species. This species is most similar to P. trachydermus . It differs from that species in the color pattern: axial zig-zag markings in P. trachydermus , spiral interrupted bands in P. heatheraikenae . The tufts in P. trachydermus consist of a single (rarely 2) moderately expanded axial thread; in P. heatheraikenae they are more pronounced and consist of 1–3 fused threads. It differs from P. coroni from Haiti in the same ways. Etymology. Named after Heather Aiken, mother of Simon Aiken ( UK); Simon Aiken donated the material.

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.