Annularisca pleurophora (Pfeiffer, 1852)

Figure 11 D–F

Type material. NHMUK unnumbered (3), specimens from Cuming collection bearing Pfeiffer’s handwriting may be syntypes;? ZMB unnumbered (1), syntype;? UMMZ 79565 (1), syntype.

Type locality. “ Honduras.”

Type figured. Pfeiffer, 1854a: pl. 40, figs. 5, 6.

Chresonymy.

Cistula pleurophora Pfeiffer, 1851: 169 [nomen nudum].

Cistula pleurophora Pfeiffer, 1852a: 262 –263; Pfeiffer, 1852c: 41; Pfeiffer, 1853a: 183 –184; Adams & Adams, 1856: 294; Pfeiffer, 1858: 131; Pfeiffer, 1859: 74; Pfeiffer, 1865: 142; Pfeiffer, 1876: 187; Fischer & Crosse, 1890: 218; Watters, 2006: 411.

Cyclostomus pleurophorum (Pfeiffer, 1852) . Pfeiffer, 1852d: 66.

Cyclostoma pleurophorum (Pfeiffer, 1852) . Pfeiffer, 1853b: 245; Pfeiffer, 1854a: 299 –300, pl. 40, figs. 5, 6.

Chondropoma pleurophorum (Pfeiffer, 1852) . Martens, 1890: 14, 16.

Ctenopoma pleurophora (Pfeiffer, 1852) . Fischer & Crosse, 1890: 188.

Choanopoma (Choanopomops) pleurophorum (Pfeiffer, 1852) . Solem, 1961: 195 –196, 198–199, pl. 10, fig. 8, map 1.

Choanopoma pleurophora (Pfeiffer, 1852) . Thompson, 1967: 227.

Annularisca (Annularella) pleurophora (Pfeiffer, 1852) . Watters, 2006: 56, 411.

Cistula pleurophorum Pfeiffer, 1852 . Thompson, 2011: 47 [possibly West Indian].

Distribution and habitat. Thompson (2011) questioned whether this species was actually part of the Central American fauna. It is regarded here as a mislabeled specimen.

Description. Shell turbinate, thin, solute except just before aperture. Only specimen seen 8.2 mm in length (non-decollate). Protoconch retained, 1.75 large, rounded, smooth pale whorls, clearly demarcated from teleoconch. Teleoconch of 3 rounded whorls. Umbilicus wide, open to protoconch. Spiral sculpture absent except for 4 widely spaced cords in the umbilicus. Axial sculpture of ca. 40 widely spaced, low lamellae, between which are 5–10 microscopic threads. Suture strongly indented. Tufts absent but the axial lamellae may render the suture serrate. Aperture nearly circular. Inner lip smooth, narrow, barely exserted. Outer lip very narrow, more or less evenly expanded, widely auriculate posteriorly, solute. Base color dingy yellow-white, no evidence of banding. Lip same color as base. Operculum multispiral, remnants of a calcareous lamella evident. Radula and anatomy unknown.

Variation in specimens. Only the UMMZ specimen was examined.

Comparison with other species. This small, smooth, turbinate species resembles no other Central American annulariid.

Remarks. There is no question that this is a species of Annularisca (Annularella) and it appears to be identical with Annularisca (Annularella) yunquensis (Pfeiffer, 1861) from the Guantánamo Province of Cuba. If this is the case, Cistula pleurophora Pfeiffer, 1852, would be the valid name for that species. But because I have not examined the type of Annularisca yunquensis (Pfeiffer, 1861), I have not placed that species into the synonymy of C. pleurophora at this time.

Original description (translated here from Latin). “Shell umbilicate, globose-turbinate, thin, longitudinal crowded striations and corded ribs, prominently sculptured, diaphanous, slightly shining, whitish-brown; spire turbinate, apex acute, corneous; suture with denticulate ribs; five convex whorls, last almost smooth, forward briefly solute; umbilicus medium sized, deep, banded with carinate angulations; aperture subvertical, ovalsubcircular; peristome continuous, simple, straight, columellar margin expanded.—Operculum normal, with thin shelly lamina, interior cartilaginous with widely separated sulcus.” 12 mm diameter.

Etymology. G. pleuron, ribs + G. - phoreus, bearer—bearing ribs.