228 
THE TANGANYIKA PROBLEM. 
female that portion of the genital duct which lies within 
the mantle cavity is dilated so as to form a large broad 
pouch, in which the ova go through their later stages of 
development. (Fig. 5). 
BATH ANALIA, MOORE. B. IIOWESII (FIG. 8). 
The remarkable form to which I gave the name Batha- 
nalia howesii is also an inhabitant of the deep water of 
Fig. io. — A single row of the lingual teeth of Bathanalia howesii. 
Tanganyika throughout the southern third of the lake. It 
is characterised chiefly by its shell which, in all essential 
conchological characters, is identical with several marine 
Jurassic fossils that have been described under the name 
Amberleya. Except for its widely different shell, Batka- 
nalia is structurally identical with Ty phobia, even the 
lingual teeth presenting only the minor differences seen 
on comparing Figs. 4 and 10. 
CHYTRA, MOORE. CHYTRA KIRKII (FIG. I I ). 
The anatomy of this remarkable form was worked out 
