68 RAFINESQUE’S 
but an ombilic. Many sp. 1. O. cuprea. Suboval, 4 spires, 
smooth, brittle, diaphanous coppery, shining, opening very large. 
In Kentucky. 
29. TRIODOPSIS, Raf. 1819. Differ Helix, opening with 3 
teeth. 2 above, 1 below, an ombilic. 1. Tr. lunula. Depressed, 
mouth narrow with thick lips, ombilie lunulated. In Kentucky. 
Forms 8. G. menomphis. 
30. XOLOTREMA, Raf. 1819. Differ from the last by no 
ombilic, opening linear. 1..X. clausa. Subdepressed, 5 spires a 
little striated, opening almost hidden. I have many more land and 
fluviatile univalves, too many to enumerate here; but I add two 
beautiful Agatinas from the south. — 
31. Agatina Variegata, Raf. 1820. Six spires, smooth, yellowish, 
variegated with brown spots near the sutures, first spire with some 
narrow coloured strias concentric Nearly two inches, from 
Louisiana. | 
32. Agatina Fuscata, Raf. 1822. Eight spires, smooth, reddish 
brown, with broad longitudinal black bands on the spires, of a lan- 
ceolate flexuose shape. Over two inches, From Texas. Both col- 
lected by Dr. Strong. 
VII. FOSSIL BIVALVE SHELLS. 
$3. Mytilus exotilus, Raf. 1820. Oblong oboval, minutely striated, 
strias broader below, curved near the sides. Breadth two thirds of 
length, thickness 4-9. From the limestone near Boon creek, Ken- 
tucky, petrified, over 2 inches. 
34. APLEUROTIS, Raf. 1819, and tract of October, 1831. N. 
G. very near mytilus, but winged and perforated. 1. Apl. pectenoides, 
Raf. Oboval, upper valve convex striated, wing well marked, lower 
valve flat, scarcely striated. Breadth 4-5 of the length, which is 
over 2 inches. 2. Apl. pusilla, Raf. Oblique oboval, flattened, 
minutely striated, wing small. Breadth ? of the length, which is less 
than one inch. Both from Knobhills of Kentucky. 
36. OXISMA, Raf. 1819. N.G. near Pinna. Base truncate, 
[4] 
end gaping, equivalve, hinge lateral plicate on one valve, angular on . 
the other. 1. O. bifida, Raf. Shell bifid by valves acute and gaping 
before, outside black and rough, sides straight, length 3-8 of the 
breadth, hardly one inch. Knobhills. | 
31. Terebratulites Eriensis, Raf. 1818. Base smooth, remainder 
