huge fish 20 Feet long w more; but 
1 know of none with similar shields. 
It is a fine perfect flat hone, yellow- 
ish white, solid, hard and heavy, 
rounded with a reniform base, 8 in- 
ches broad and 6| long, half an inch 
thick, edge entire thick, surface 
above nearly smooth, with an Areo- 
lar depression round the centre, 
which has several unequal chinks. 
Lower surface entirely covered with 
vermicular anastomosed elevations, 
forming irregular pits and proemi- 
nences. Is it the bony shield of the 
head of Megasaurus ? or some other 
huge fossil reptile? 
7. Jaw bone of the Jhnblodon 
grunniens of my Ichthyology of the 
Ohio, with the large grinding teeth 
that serve to crush the Unios, his 
food. 
III. CRUSTACEA, 
8. Trilobites Cephaleurya , Raf. 
disc. 1817. Head very broad, granu- 
lar before, eyes convex dotted, body 
with eleven segments, tail with se- 
ven segments. In the mountains 
Alleghany and Ca-t skill, but very 
rare, in sandstone strata silicified, 
9. Trilobites Simla, Raf. 1819. 
Head smooth, very large, resembling 
a monkey’s face, 4 small furrows 
near the eyes, not dotted, body and 
tail with few segments. Found 
loose silicified in the Knobhills of 
Kentucky, in the bed of Salt River. 
10. Trilobites Grcinulata , disc. 
1825. Head quite granular, not 
so broad as the body, eyes very 
proeminent and granular, body 
and tail with 20 narrow proeminent 
segments. Fine large sp. over 4 
inches long, silicified, from the 
Limestone of the Shenandoah Val- 
ley in Virginia. 
11. IS OC TOMES A, Raf. N. G 
disc. 1 820, published 1821 in the 
Kentucky Gazette, since published 
also in 1824 by B e Kay with the 
name of Octomeris . I had 2 sp. of 
It, one beautiful 8 inches long, from 
the Limestone strata on Licking 
River, Kentucky. 'The G. differs 
from Trilobites by head and tail 
equal, body with 8 equal segments. 
12. RIL0BITES, Raf disc. 1819. 
Head bilobed oculated; 2 sp. B . lu- 
tt«2a£tf,lunular head; 2 BUobaia , head 
with two obtuse lobes. Roth From 
the Knobhills of Kentucky. I have 
many other fossil Crustacea, and 
have seen 15 sp. altogether, de- 
scribed in a Monograph in 1822. 
IV. FOSSIL UNIVALVE SHELLS. 
13. ERPILITES, Raf. N. G. 
or perhaps a S. G. of Trochites . 
Opening oval, subquadt angular by 
the end being nearly truncate, colu- 
mella with a twisted fold and end- 
ing with an acute point. All the 
sp. from the limestone and sand- 
stone of Ohio and Kentucky, where 
other Univalves are very rare. I 
have 7 sp. at least and shall here 
describe & of them. The name 
means creeping. Although these 
shells are marine, they appear to ap- 
proximate very near to the Fleur o~ 
cera and Melania , now living in the 
Rivers of the same region. 
14. Erpilites Multistriata , Raf. 
1818. Suboval 3 spires with many 
spiral ribs and minutely striated 
obliquely. Fine perfect specimen 
from sandstone of Knobhills, one 
and half inch long, with crystals 
inside. 
15. Erpilites Platenia, Raf. 1820. 
Broad depressed, 3 spires smooth, 
the first very large with a broad 
ibi angular flat raised band, becoming 
a spiral angle in the other spires. 
Large sp. two inches broad, silici- 
fied, from the limestone. 
16. Erpilites Ohiemis , Raf. 1818. 
Suboval, 5 spires smooth, each end- 
ing by a spiral angle on the upper 
edge. Limestone of Ohio state, one 
inch,. 
17. Erpilites Carinata , Raf. 1818. 
Oblong smooth, 5 spires carinated 
in the middle spirally. Near Lex- 
ington in limestone, small, half an 
inch, seldom petrified. 
18. j Erpilites Stenotenia , Raf. 
1821. Oblong smooth, 4 or 5 spiles 
with a narrow depressed spiral band. 
Limestone of Kentucky. 
V. FLUVIATILE UNIVALVE 
SHELLS. 
19. Fleurocera Gmula , Raf. 
1818. Seven spires, the first with 
two or three small angles, the others 
with only one. River Kentucky. 
‘My G, Fleurocera » 1819, is perhaps 
