Jawless land snail Sinorachis, a new bradybaenine genus from China (Eupulmonata, Camaenidae).

Min Wu,Zheyu Chen,Liwan Zhang

doi:10.3897/zookeys.893.38445

Abstract

A new land snail species that represents a new genus is reported from Hubei, China. The snail has a conical shell with pits and/or granules on embryonic whorls and a smooth teleoconch with straight peristome. The head of the animal has a developed wart. The mantle lobe is only developed on the left side. At the front of the buccal mass there is no chitinous jaw that is without exception seen in Chinese camaenids. Its radular teeth are usually slender and tongue-shaped, not typical in bradybaenine snails. The genital system is typical of Bradybaeninae and is characterized by the absence of a membranous sac surrounding the terminal genitalia, penial caecum or flagellum; a well-developed penis sheath; a symmetrical dart sac apparatus; and one distally branched mucous gland. The new species Sinorachis baihu Wu & Chen, gen. and sp. nov., is assigned to the type species of the new genus, in which all the known Chinese Rachis species are included. Thereby, the new genus is composed of three species, namely Sinorachis onychinus (Heude), comb. nov., Sinorachis aureus (Heude), comb. nov. and the new species.

Highlights

Rachis Albers, 1850 is an enoid genus comprised of many known species from Africa and India (Schileyko 1998b)
Two Chinese land snail species with conical shells were assigned to this genus based on shell morphology (Gredler 1887; Yen 1939; Wu 2018)
Möllendorff (1901) placed them in Buliminus and thought they appeared to be related to the group, including Bulimus cantori Philippi, 1844 (= Mirus cantori), he wondered about the absence of an angular nodule that is ubiquitously observed in the Chinese enids

Summary

Introduction

Rachis Albers, 1850 (type species Bulimus punctatus Anton, 1838; SD Martens in Albers 1860) is an enoid genus comprised of many known species from Africa and India (Schileyko 1998b). The shells of Chinese Rachis species are, in many respects, untypical of the bradybaenine genera. The genital pattern of this species, totally differs from those of these enoids; rather, the developed dart sac apparatus suggests it belongs to the camaenid subfamily Bradybaeninae.

Results

Conclusion