10 EKDODONTIDJE. 



16. Trochomorpha trilineata, Morcli. 



Nanina (Videnci) sulcipes, var. trilineata, Morcli, Journ. Conchyl 



1876, p. 355. 



Discus sulcipes, var. trilineata, Godwin-Austen, P. Z. S. 1895, p. 442. 

 Discus trilineatus, Godwin-Austen, Proc. Malac. Soc. London, i, 



1895, p. 285, pi. 19, fig. 2 (anatomy). 



This form was originally described as a variety of T. sulcipes, 

 and a very short description of it was given by Morch : " T. pallida, 

 carina Candida, utrinque linea brunnea." Lt.-Col. Godwin-Austen 

 in P. Z. S. 1895, also considered it a varietal form only, but in Proc. 

 Malac. Soc. London he raised it to specific rank, at the same time 

 giving an account of its anatomy. There is a discrepancy as to 

 habitat, for in the latter paper he mentions Great Nicobar, whereas 

 in the former Camorta is indicated, which corresponds with the 

 original locality given by Morch. 



Hob. Nicobar Islands : Camorta (Roepstorff}. 



Family ENDODONTID^E, Pihbry. 

 Subfamily THYSANOTIN^E, Godwin-Austen. 



Genus THYSANOTA, Albers. 



Thysanota (as section of Nanina), Albers & Martens, Die Heliceen, 

 ed. 2, 1860, p. 63 ; (as section of Trochomorpha) Pfeiffer, Malak. 

 Blatt. xxiv, 1877, p. 7 ; (as section of Eulota} Pilsbry, Man. 

 Conch, ser. 2, ix, 1895, p. 207 j Godwin-Austen, Moll. India, ii, 

 1907, p. 189. 



TYPE, Helix guerini, Pfeiffer. 



Range. Southern India and Ceylon. 



Original description : " Testa anguste umbilicata, trochiformis, 

 tenuis ; anfractus 7^- vix couvexiusculi, basi carinati, pilis rigidis 

 ciliati, ultimus interne subplanatus, medio impressus ; apertura 

 angulato-lunaris ; peristoma simplex, acutum, margine columellari 

 brevissime expansiusculo." 



Until the anatomy of T. crinigera was investigated by Lt.-Col. 

 Godwin-Austen in 1907, and its relation to Endodontida3 estab- 

 lished, the systematic position of the genus had remained uncertain. 

 Von Martens placed it between Rotula and Nigritella, Pfeiffer 

 classed it under Trochomorpha, while Prof. Pilsbry with some 

 doubt considered it as having affinity with Plectotropis, and he 

 therefore ranged it under Eulota as a section. Thysanota, Phila- 

 lanka, and Ruthvenia, on conchological grounds alone, form a very 

 natural group, as proposed by Godwin-Austen (subfamily Thy- 

 sanotina3), and one wonders how this idea has not occurred to 

 anyone before. 



17. Thysanota tabida, Pfeiffer. 



Helix tabida, Pfeiffer, Malak. Blatt. ii, 1855, p. 106; ibid.,Novit. 

 Conch, ser. 1, i, 1855, p. 45, pi. 12, figs. 11, 12. 



