24 F. Stoliczka — Land-sTiells of Penang Island. [No. 1, 



All have very sharply pointed cusps, the central has two small lateral 

 denticles on either side ; on the outer ones these denticles almost entirely 

 disappear. 



The genital organs are distinguished by a great length of the utei'us, 

 at the end of which lies a large albuminous («y.) and hermaphrodite gland 

 (7/y.). The seminal receptacle (^rs.) is a long, pedunculated, spacious bag 

 which includes a peculiarly twisted, horny organ, provided on the concave side 

 with short crispate appendage. It is the same problematic organ which I 

 described in Sesara infrendens, Gld., and Macrocldamys [Durgella] lionesta, 

 Gld., (Comp. J. A. S. B. XL., Pt. II, p. 242 and 250, pi. xvi, fig. 5 and 6, 

 and pi. xvii, fig. 13). Whether this structure represents the amatorial 

 organ and whether that which we call a seminal receptacle really possesses the 

 function which we attribute to it, appears to be as yet an open question. 

 In the present species I found the terminal end of the so-called seminal 

 receptacle filled with a milky substance, which under a high power exhibited 

 a quite irregular flaky appearance. 



In other respects the present species does not offer any anatomical 

 peculiarities. The oesophagus is comparatively thin, long, cylindrical. The 

 kidney, situated near the end of the rectum, is very large, of a broadly 

 triangular shape ; the liver enormously developed. 



Some years passed the Vitrince had been classed as a subfamily of the 

 Helicidce ; more recently they had been by various authors treated with the 

 ZonitidcB, in the Oxygnathe group of Helicacea. I think the older classi- 

 fication is preferable, as entered by Binney and Bland in their Land and Fresh- 

 water shells of N. America. But I would prefer to give them, together with 

 Helicolimax, Hyalina and their allies, a position intermediate between the 

 two families. They combine indeed several of the characters of both. 

 Although they do not possess a terminal mucous gland on the end of the foot 

 (as all ZonitidcB do), they have a more or less distinct pedal row, and the sole 

 appears to be often divided by longitudinal grooves. The jaw is entirel}^ or 

 partially finely transversely striated, not quite smooth, as usually in ZonitldcG, 

 and not ribbed, as in true SelicidcB. However, the teeth, particularly the 

 outermost laterals, have more the pointed character of the former than of 

 the next family. 



Fam. Helieid89. 

 Trachia=* PENANGE^iTsis, n. sp. PL iii, figs. 1 and 18-20. 

 T. suborbiculata, alta, spira breviter elevata, obtusa, modice sed profunde 

 umbilicata, tenui, fere cornea, cuticula luteo-fusca dense et breviter pilosa 

 induta, unicolore ; anfractibus 4*5, convexis, sutura profunde subcanaliculata 

 junctis, ultimo ad peripheriam uniforme convexo, ad aperturam paulo descen- 

 * Com^pare, Stoliczka in Journ. A. S. B , vol. xl, Pt. II, 1871, p. 223. 



