INDEX TO PLATES. 
(From American Conchology.) 
late 
1. 
Astarte castanea. 
i 4 
ii. 
Pandora trilineata. 
i i 
iii. 
Oliva litterata, Lam. 
i ( 
iv. 
Unio triangularis, Barne 
u 
V.. 
Lower figure. 
suLCATus, Lea. 
4. 
Upper 
U 
“ RIDIBUNDUS. 
i i 
vi. 
‘‘ MONODONTA. 
u 
vii. 
DeLPHINULA L.AXA. 
viii. 
Upper 
Melania nupera. 
ll 
Middle 
“ “ young. 
1 i 
Lower 
‘‘ DEPYGIS, 
u 
ix. 
Lutraria lineata, 
i i 
X. 
Upper 
ii 
Paludina decisa, 
a 
Lower 
4 i 
a ii 
Middle 
“ VIVIPARA, L. 
i i 
xi. 
Anodonta suborbiculata. 
xil 
Upper 
U 
Nucula limatula. 
u 
Middle 
i i 
ii ii 
1 • 
Lower 
ii 
ii ii 
i 1 
Right 
ii 
‘‘ la: vis. 
u 
Left 
U 
“ CONCENTRICA. 
i 1 
xiii. 
Upper 
ii 
Helix albolabris. 
■u 
Lower 
^6 
“ THYROIDUS. 
4 
xiv.. 
Unio ellipsis. Lea. 
i 
XV. 
SUBTENTUS. 
1 i 
xvL 
UNDULATUs, .Bames, 
w i 
xvii. 
“ ABRUPTUS. 
- 
xviii. 
SOLECURTUS COSTATUS. 
xix. 
Fulgur pyruloides. 
XX. 
Glandina truncataj Gm. 
... 
xxi. 
Alasmodonta confragosa. 
xxii. 
Unio phaseolus, Hildreth. 
The lower figures represent the bran- 
chial oviducts ; that of the middle 
is a lateral view of a portion, of the 
natural size, as distended by the 
included eggs. On the right is 
represented the summits of the 
tubes of which this organ is com- 
posed. On the left are two of the 
tubes magnified, 
xxiii. Unio tetralasmus„ 
XXiv. DEHISCENS, 
