MOLLUSCA OF INDIA. 99 



'Hah. in insula Ceylon {Layard; jj, Thwaifes). 



" DifFert ab H. suhopaca. Sculptura subtiliore, minus regulari, 

 anfractu ultimo minus dilatato, &c." 



Original description {Helix suhopaca, Pfr.) : — " H. testa semi- 

 obtecte perforata, conokleo-depressa, solidula, superne subarcuatitn 

 costulata, basi radiato-striata, suhopaca, pallide rubello-cornea ; 

 spira hreviter conoidea ; sutura simplex, impressa ; ayifractibus 6^, 

 vix convexiuseulis, ultimo noii descendente, basi plaiiiusculo ; apertura 

 ohliqua, lunari, intiis margaritacea ; peristomate simplice, recto, 

 tnargine columellari declivi, subincrassato, ad perforatiomm triangu- 

 latim dilatato. 



"Diam. maj. 17, min. 14|, alt. 9 mill. 



" Hab. in insula Ceylon." 



The specimen dissected was obtained at Ambagamuwa(0. Colleft). 

 Collett says in his paper on the shells of this district : — " This is 

 one of our commonest species. It is rather variable in size and in 

 depth of colour. The animal, which is black and white, is dimly 

 visible through the shell. Habitat amongst leaf-mould around the 

 roots of plants." 



Generative organs. The lower main sheath of the male organ 

 (Plate LXXXVII. figs. 1-16) is very short, from the generative 

 aperture upwards ; it then diminishes in section and is folded into a 

 large loop confined by a strong broad muscle. Xear the return 

 portion of the free loop is a short stout portion, the muscular diverti- 

 culum or ea?cum, to which is attached the retractor muscle. Near 

 the same place is the short kalk-sac, and to this the vas deferens 

 joins (figs. 1 b, 1 c). In this specimen at this junction a very 

 remarkable set of finger-like processes, one overlying the other, was 

 very conspicuous, denoting the formation of the spermatophore, 

 in this respect differing very much from other species. 



The spermatheca is globose and short. The amatorial organ 

 well developed. There is neither a right shell-lobe nor a left 

 shell-lobe. The left dorsal lobe is divided into a large anterior and 

 a small elongate narrow posterior portion. 



The formula of the radula is : — 



72 . 1 . 13 . 1 . 13 . 1 . 72 



86 . 1 . 86 



The central tooth is tricuspid, narrow, elongate, with small cusps ; 

 the median teeth are tricusjiid, the inner cusp indicated by a slight 

 notch on the inner side ; the laterals are long, curved, and bicuspid, 

 the outer cusp considerably below the point of the inner. 



This agrees in every respect with Semper's description of the radula 

 of suhopaca, but he gives the number of teeth in the row as less ; 

 this is not important : it sometimes happens that the edge of the 

 radula is incomplete, and the very minute teeth are not counted ; 

 therefore the number of the broad median teeth, and the 2 or 3 

 transition teeth, is of much more importance. 



