244 
THE TANGANYIKA PROBLEM. 
B. MINOR, MOORE (FIG. 24). 
During the second Tanganyika expedition a new species 
of Bythoceras was obtained, which has not yet been figured 
or described, and to which I have given the above distinc- 
tive name (Fig. 24). This form is somewhat smaller 
than B. kowesii and possesses a less marked epidermis. 
In other respects it does not differ from the original type of 
the genus. 
Fig. 26. — The lingual dentition of Paramelania crassigramtlala. 
PARAMELANIA, SMITH. — P. DAMONI (FIG. 2 j). 
In its general structural peculiarities, the genus Para- 
melania closely resembles Typhobia and the preceding 
group of forms, but it differs from them all in several 
marked peculiarities. Thus, the shell (Fig. 27) is highly 
characteristic, and in form and sculpture indistinguishable 
from the old marine Jurassic form Pur Purina bellona ; 
it has also generally more apparent epidermis, though the 
living shells may at the same time be quite without. 
In the mantle cavity the parts are arranged almost 
