Boucardicus ambindaensis, Balashov, Igor & Griffiths, Owen, 2015

Balashov, Igor & Griffiths, Owen, 2015, Two new species of minute land snails from Madagascar: Boucardicus monchenkoi sp. nov. and B. ambindaensis sp. nov. (Caenogastropoda: Cyclophoridae), Zootaxa 4052 (2), pp. 237-240 : 239

Boucardicus ambindaensis sp. nov. Fig. 1 b.

Type locality. Dry deciduous forest among the large vertical limestone rocks (tsingy), west side of Tsingy Beanka reserve, east of Ambinda and Belitsaka villages, around 50 km east of Maintirano town, central-western Madagascar. 18.04465°N 44.501117°E, 300 m altitude (from GPS).

Material. Holotype ( IZAN GT 4631) and 9 paratypes (6 in IZAN, GT 4632, 3 in AMS, C.483541) are directly from the type locality (collected by R. Randalana & G. Middleton on 2th October of 2006), 3 more paratypes (2 in IZAN, GT 4633, 1 in AMS, C.483542) were collected in other locations in south-eastern part of Tsingy Beanka reserve east to Belitsaka village on 3th October of 2006 (from GPS: 18.054167°N 44.533333°E, 350 m altitude)

Etymology. From occurrence near Ambinda village.

Diagnosis. Shell is pupilloid-like, almost smooth (with weak radial lines), aperture is almost round, with single columellar lamella relatively deep in aperture that goes through almost whole body-whorl inside it and single palatal lamella in the begging of body-whorl (could be visible through wall of shell). Basal peristome is almost complete, slightly reflected.

Dimensions. Height of shell 2.4–2.5 mm, diameter 1.2–1.3 mm (holotype 2.4x 1.2 mm). Aperture height 0.7 mm, aperture width 0.8 mB. Hight of body whorl—1.1–1.2 mB. Diameter of embryonic whorls (~1.5) 0.3–0.4 mB. Diameter of 3rd whorl— 0.8 mm.

Shell is pupilloid-like, ovate-pointed, moderately thin-walled, translucent, of 5 moderately convexed whorls (sometimes 5.25). Suture is moderate. Body-whorl periphery round. Coloration is light-brown. Whole shell is smooth (only somewhere weak radial lines are present), except post-constriction swelling that irregularly striated or even sometimes almost ribbed. Body-whorl constriction occurs about 0.6 whorl before the peristome. The post-constriction swelling is moderately weak, about 0.3 mm width, placed left to columellar peristome. Aperture is almost round, with a single clear columellar lamella near edge of aperture in the middle of columellar peristome. Columellar lamella is placed perpendicularly to the columellar peristome, goes almost through whole body-whorl on columella (one paratype was studied inside). Inside body-whorl there is a long palatal lamella that could be visible through wall of the shell in fresh specimens. In holotype, as it looks from outside, palatal lamella goes from beginning of body-whorl till almost last 0.5 whorl (length about 0.7 mm). In paratype that was studied inside (old not translucent shell) lamella is short, 0.25 mm, but large and high. Peristome is almost complete, slightly interrupted (in upper part in place of connection with penultimate whorl). Basal peristome slightly reflected. Lip moderate. Umbilicus drop-shaped.

Variability. All 13 type specimens are very similar in the size, shape, sculpture, swelling and aperture, including 3 specimens from second locality. Therefore same to the previous species known variability of the shell is low here.

Identification. From the other pupilloid-like species of the genus except B. pseudogastrocoptus it differs by its round aperture with almost complete peristome. From the most—by the well developed both columellar and palatal lamellae. From B. pseudogastrocoptus it differs by presence of palatal lamella and much more developed columellar lamella, by absence of lip and by smaller shell.

Distribution and habitats. It lives in leaflitter in deciduous forests among the large vertical limestone rocks (tsingy) placed on altitude of 300–350 m, in Tsingy Beanka reserve east of Ambinda and Belitsaka villages, around 50 km east of Maintirano city, central-western Madagascar.

Figures

FIGURE 1. Holotypes of Boucardicus monchenkoi sp. nov. (a) and B. ambindaensis sp. nov. (b).