MOLLUSCA OF INDIA. 13 



with the vas deferens given off' at the extreme distal end, close to the 

 phnul ( f) which represents the flagelhim. In the second specimen 

 dissected this is well shown (fig. 16); it is small, short, slightly 

 hooked, not flat and notched as in O. ochracea. Further on, in a 

 species from Cachar, a small variety of G. garoense (turreted and 

 elongate) a similar short flagellum was found (Plate CLXV. fig. fi). 

 The spermatheca (sji.) is an elongate sac on a long stalk. The 

 retractor muscle is given off about half-way down the side of the 

 sheath. 



The animal (flg. 1 ) can withdraw into the shell as far back as 

 the three last whorls. The sole of the foot is widdy segmented 

 from side to side. Contracted in spirits the animal has about 8 

 whorls (fig. 1 c). There are narrow right and left dorsal lobes, 

 and on the cohimellar side a muscular cylindrical mass fills the 

 characteristic groove. 



Glessula lokgispira, n. sp. (Plate CLIX. fig. 2.) 



Loealitij. llarhichu, Sikhim ( W. Robert). No. 3593 B.3I. 



Animal. Foot short, rich grey black, surface minutel}- papillate, 

 in strong contrast with the sole, which is pale ochraceous, narrowly 

 segmented transversely. 



Length to last whorl 100 : 39. 



The jaw is slightly convex, very thin and transparent, and under 

 high power is seen to be made up of very numerous narrow 

 elongate plates. 



Size : length 37 ; m.ij. diam. 8-75 mm. 



From the Uechila Peak on Sikhim border and Western Bhutan, 

 Mr. Wm. llobert sent me five specimens (No. 28 B.M.), sepia- 

 brown in colour, and with far stronger sculpture, which may be 

 considered a local variety. The largest has 12 whorls, and 

 measures 37-75 X 9-25 mm. 



Anatomical investigation shows that there are two very distinct 

 sections of Glessula, and so far they conform to shell character — for 

 how great conchologically is the difference between the turreted 

 very long species and the glossy, oblong-conoid forms ? The short 

 oblong species, such as G. gemma, have yet to be examined — they 

 may have some character of their own, viewed anatomically. 



in this genus and this particular species it may be said I am 

 laying considerable, even undue stress, on variation in a single 

 organ — the penis —and of that only a part. This will be noted and 

 felt even more by conchologists, some explanation therefore seems 

 necessary for entering into physiological details. The flagellum is a 

 very small organ, but one of great importance ; in the developmental 

 life of the animal it has a most important part to play. Within it 

 is formed the spermatophore, which is filled with spermatozoon, and 

 eventually, in the act of copulation, is transferred to the spermatheca 

 of the other individual — its spines keep it in position on its passage 

 and retain it there. In different genera, it takes on more or less 

 very complicated forms and becomes a very important character, 



