76 COLLINGE: NON-OPERCULATE LAND AND FRESHWATER MOLLUSCS. 



link between the genus Dcmiai/anfia oi Insal and P((riitari(jn of Fischer. 

 Cryptosemelus, n. gen. 

 Cryptosemelus gracilis, n. sp. 



ri. V, figs. 37-39. 



Animal dark blue, body marked by prominent oblitjue lines running 

 dcnvnward and backward, dorsum posteriorly keeled ; mantle rises 

 upon the shell anteriorly and laterally, on the right side it is produced 

 into a wing-like extension covering the apex of the shell, while on the 

 left side antero-laterally there is a smaller lappet. Rugae only visible 

 on the head and anterior parts of the body. Caudal mucous pore 

 very small. Peripodial groove distinct. Foot-fringe bright }ellow, no 

 lineoles. Foot-sole divided into median and lateral planes. 



Length (in alcohol) 19*5 millim. 



Shell yellow, thin, membranaceous, whorls, 3^, last whorl very 

 large. 



Hah. — Bukit Besar, vState of Nawng Chik. 



Known to the natives as the " Dancing Slug." 



Girasia. Gray (lmh C;i)d\v.-.\ust.). 



Girasia peguensis, The(jb. 

 PL iv, figs. 13-14. 



G ii-asia 2'eguensis, Theob. : J. As. Soc. Bengal, 1864, p. 244. 



Girasia? peijueiviis, Godw.-Aust. : P.Z.S., 1880, p. 294. 



Girasia pe(juensis, Godw.-Aust. : Moll, of India, 1888, vol. i, 

 p. 227, pi. lix, figs. 6-6d. 



Hah. — Belimbing, State of Ligeh. 

 It has been pointed out by Godwin- Austen (12) that so far as the 

 mantle is concerned, this species forms a connecting link between 

 Girasia and Ausfenia, Nev (em. G.-A.); this author also draws atten- 

 tion to the fact that the right and left tentacular retractor muscles 

 differ from one another, which I am able to confirm: the left one is joined 

 to the buccal retractor and both of these have their origin posterior to 

 the shell, while the right one remains distinct and originates from the 

 posterior border of the visceral mass. 



The Generatire Organs (PI. iv, figs. 13-14). — The generative 

 organs of this species have not previously been described. The 

 vagina is a wide cavity, similar in detail to that in ''/. hnokeri, Gray. 

 The receptaculum seminis is much longer than in the last mentioned 

 species, and has a distinct duct " hich gradually widens into the 

 elongated head (PI. iv, fig. 13, r.iJ. and r.s.). In life it lies at the 



