MOLLUSCA OF INDIA. 13 
with the vas deferens given off at the extreme distal end, close to the 
gland (f) which represents the flagellum. In the second specimen 
dissected this is well shown (fig. 16); it is small, short, slightly 
hooked, not flat and notched as in G. 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. 6). 
The spermatheca (sp.) 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 (fig. 1) can withdraw into the shell as far back as 
the three last whorls. The sole of the foot is widely segmented 
from side to side. Contracted in spirits the animal has about 8 
whorls (fig. ] c). ‘There are narrow right and left dorsal lobes, 
and on the columellar side a muscular cylindrical mass fills the 
characteristic groove. 
GLESSULA LONGISPIRA, n. sp. (Plate CLIX. fig. 2.) 
Locality. Rarhichu, Sikhim (W. Robert). No. 3593 B.M. 
Anmal, Foot short, rich grey black, surface minutely papillate, 
in strong contrast with the sole, which is pale ochraceous, narrowly 
eric nied 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; maj. diam. 8°75 mm. 
From the Rechila Peak on Sikhim border and Western Bhutan, 
Mr. Wm. Robert 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, aud 
measures 37°75 xX 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 
telt even more by conchologists, some explanation therefore seems 
necessary for entering into physiological details. The flagellum isa 
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, 
