. ANODON.—Ptare XIV. 
short, lateral margin oblique, ventral margin straight; 
anterior side short, rounded, subcuneate above. 
MS. Cuming’s Cabinet. 
Hab. Bengal rivers. 
Differs from Anodon subcrassa in the straightness of 
the ventral margin and obliquity of the lateral margin. 
Species 50. (Mus. Cuming in Brit.) 
ANODON 
crassa, subarcuatd, oblonga, rugis crebris concentricis 
SUBRENIFORMIS. 
et striis radiantibus reticulata, viridi-fulvescenti, intus | 
albé, prope marginem subceruled ; latere postico an- 
gulato, termino acuminato, margine dorsali recto, 
margine laterali oblique convero, medio depresso, mar- 
gine ventrali arcuato ; latere antico breviusculo, mar- 
gine dorsali brevi, umbonibus levigatis, prominenti- 
bus. 
THE SUBRENIFORM ANODON. 
thick, somewhat arched, oblong, reticulated with 
close concentric wrinkles and radiating striz, brown- 
Shell compressed, solid, 
ish-green, white within, bluish towards the margin ; 
posterior side angular, acuminated at the end, dor- 
sal margin straight, lateral margin obliquely convex, 
middle depressed, ventral margin arched; anterior 
side rather short, with short dorsal margin, umboes 
smooth, prominent. 
An. testd compressa, solid, | 

SOWERBY. 
Hab. Lake Nyassa. 
In form resembling Ax. Senegalensis, but much flatter 
and with a more reticulated surface. 4x. Senegalensis is 
also characterized by a radiating posterior rib, which is 
wanting in the present species. 

Species 51. (Mus. Cuming in Brit.) 
ANODON FERUSSACIANA. 
tumidd, tenui, laevigata, medio depressd, olivaceo- 
An. testa ovato-subelongatd, 
viridi, subaurantid, fasciis angustis numerosis ob- 
secure radiata; latere postico oblongo, superne angu- 
lato, subalato, termino rotundo, margine ventrali ad 
medium contracto; latere antico subrotundato, siperne 
angulato, umbonibus ovalibus levigatis, ad apicem mi- 
nute undulatis. 
Frrussac’s ANopoN. Shell ovate-subelongated, tumid, 
thin, smooth, depressed in the middle, olive-green, 
slightly orange, obscurely rayed with numerous nar- 
row bands; posterior side oblong, angular above, 
subalated, end round, ventral margin contracted in 
the middle; anterior side rather rounded, with an 
angle above, umboes oval, smooth, minutely undu- 
lated at the point. 
Lea, Trans. Amer. Phil. Soe. vol. v. pl. 6. 
Hab. Sciato River, near Columbus, Ohio. 

