460 Mr. W. T. Blanford on the Classification of 
the tube opens externally in the peristome itself. Now, there is 
a small variety of Streptaulus Blanfordi (which perhaps has 
claims to specific distinction) in which precisely the same takes 
place, the tube not running backwards along the suture, but 
opening in the peristome. In no character of the shell ean 
Streptaulus be considered to agree with Alyceus; nor, I think, 
can a generic separation from Raphaulus be founded upon the 
very slight variation in the sutural tube, in the course of which 
there is quite as great a diversity between R. chrysallis and R. 
bombycinus as between either of these and Streptaulus; and if 
the distinction be preserved, it must be founded upon another 
character. Such a character is presented by the form of Strep- 
taulus, which, in place of being flattened ventrally, and having 
the upper whorls distorted as in Raphaulus, has all regular as 
in Pupina. But I doubt if this character alone be of more than 
subgeneric value, and I should therefore conclude that the pre- 
sent type is a subgenus of Raphaulus, and that it tends to con- 
nect that-genus, not with Alyceus, but with Pupina. 
I regret that I have not noted the animal of Streptaulus. It 
is probably similar to that of Raphaulus. Should the soft tube 
leading to the air-chamber prove to be wanting, there will be 
better grounds for generic distinction. 
18. Purina, Vign. 
Only four species of this form are known from Burma and 
the neighbouring countries, viz. :— 
P. imbricifera, Bens, Khasi Hills. 
P. artata, Bens. Molmain. 
P. arula, Bens. Molmain. 
P. Peguensis, Bens. astern Pegu. 
P. artata also occurs in Arakan and throughout the Irrawaddy 
valley as far north as Ava. It is a somewhat variable shell—one 
variety, from the neighbourhood of Prome and Thayet Myo, 
being somewhat more globose than the type, and having a rich 
orange peristome. 
No member of this genus has yet been found upon the Hima- 
layas, where Streptaulus alone represents the group, the mem- 
bers of which diminish greatly in number towards the north. 
The animal possesses no peculiarities. It is almost colourless, — 
with short tentacles and distinct black eyes at the base, a mode- 
rate oval foot with the sole undivided, and short proboscis. It — 
differs from Cyclophorus and its allies only in the shorter and | 
less subulate tentacles and rounder foot. 
19. Hysocystis, Bens. q 
The animal of H. gravida, Bens., is similar to that of Pupina; ee 
