Family TEOCHOMORPHID^. 



Genus TROCHOMORPHA, Albert. 

 Trochomorpha, Albers, Die Heliceen, 1850, p. 116; Martens, Die 



London, i, 1895, p. 284. 

 TYPE, Helix trochiformis, Fer., from Tahiti. 



Range. India, Burma, Andaman and Nicobar Islands ; Farther 

 India and adjacent islands ; China and Formosa ; Japan and 

 Loo-Choo Islands ; Malaysia ; Philippine Islands ; New Gruinea, 

 Admiralty and Louisiade Archipelagoes; Pelew, Caroline, Mar- 

 shall, Solomon, New Hebrides, Fiji, Navigator, Tonga, Society, 

 and Sandwich Islands. 



Original description: "Testa trochiformis, plerumque aperta 

 umbilicata, angulata vel carinata, apice obtusa, striatula, opaca, 

 subsolida, fusca, concolor vel fasciata; arifr. 5-8, supra et infra 

 plauati ; apertura depressa, obliqua, secunformis vel angustius 

 lunata, peristoma rectum, simplex, margine columellare saepius 

 paulum incrassato, sensim in basalem trariseunte. 



Maxilla laevis, arcuata, medio saepius rostrata. Pallium non 

 ultra aperturam testae productuin." (Martens, 1867.) 



The genus Trochomorpha was established by Albers in 1850. 

 He included sixteen species, not only of Asiatic and Polynesian 

 origin, but also one from Central America, two from the Ber- 

 mudas, and one from the Canary Islands. Of the sixteen species, 

 eleven have since been referred to other genera. No type was 

 mentioned. In 1860 von Martens, in the revised edition of 

 Albers' work, gave a list of 31 species, having eliminated some 

 and added a number of others, comprising several which have no 

 affinity with the genus, He indicated trochiformis as the type. 

 In the ' Preuss. Exp. Ost-Asien ' he amended and amplified the 

 description, which bears evidence of a better conception of the 

 limits of the group. It was, however, left for Prof. Pilsbry, in 

 his epoch-making work on the Helicidce, to place the genus 

 on a sound and permanent basis by giving anatomical details of 

 several forms, and enumerating all the species known at the time. 

 Although including it in his work on Helicidce, he distinctly states 

 that he considers Trochomorpha " a somewhat aberrant genus of 

 Zonitidce." Further anatomical details of the genus were con- 

 tributed in 1895 by Lt.-Col. Godwin-Austen, who, however, 

 retains the subgeneric name Discus, which, as Pilsbry has demon- 

 strated, is not available in this group, Fitzinger having previously 

 employed it for H. rotundata and its allies, so that Videna of 

 Albers has to be employed instead. 



