1871.) Proceedings of the Asiatic Society. 111 
men of the latter measured : larger diam. 8, smaller diam, 7:5, 
total height 8 m.m. 
The internal anatomy (fig. 3) does not essentially differ from that 
of other Prosobranchiate Gastropoda, The buccal parts in the mouth 
are soft, fleshy, with the usual cartilaginous valves internally. I 
have not observed a trace of a separate jaw. The cosophagus passes 
through the nervous ring, beyond which the salivary glands are 
situated. Stomach large, black ; it had vegetable matter inside, the 
animal having apparently been living on minute alge. Intestines 
verylong. The uterus in the female is dise-like, large, flattened, of 
a greyish color ; the ovarium very large, occupying the greater 
portion of the middle and also mostly of the posterior surface, 
and of the inner or collumellar side ofthe body. In a full grown 
female, (examined in March) the eggs were somewhat more than 
one half millim. in diameter, yellow, with a large transparent, 
excentric, nucleus, enclosing a minute nucleolus. 
In the male, the testis is situated, similarly to the ovary in the 
female; it is generally of a pale yellowish colour and the sperma- 
tozoa are rather short, extremely thin, gradually thickened towards 
one end. In some specimens the testis occupied the whole of the 
surface of the terminal 14 whorls. The vas deferens lies along 
the ventral (or columellar) side and is of very great length ; it was 
filled with well developed spermatozoa. 
The kidney is large, elongately ovate, grey, situated behind the 
gills. The liver is greenish, consisting of two anterior smaller lobes 
while a larger, much subdivided, lobe occupies the terminal portion 
of the body. 
e gills consist of a single rather narrow plume, composed of 
thin fillets which are grown to the upper side of the gill-cavity. 
The fillets are on the right side very finely prolonged and partially 
become branched, resembling in this respect the breathing organ of 
pulmoniferous Mollusca; the same form is already indicated in 
several of the more terrestrial than aquatic Litforine. To the right 
of the gill is a narrow thickening, which is generally stated to 
be a rudiment of a second plume ; it is barely indicated in this 
species. 
The radula is narrow, very long, from 10-14 m.m.; the greater 
