200 PALEOZOIC FISHES OF NORTH AMERICA. 
PHYSONEMUS STELLATUS, 0. Sp. 
Plate X XI, Fig. 12. 
Spine relatively small, much compressed, broad at the base, rapidly 
narrowing to the summit, which is strongly recurved; posterior margin 
formed by extensions of the sides until they become extremely thin and 
widely separated by the continuous posterior furrow; sides above the un- 
ornamented base covered with lines of numerous, small, stellate, enameled 
tubercles, which on one side reach quite to the margin, on the other fade 
out about two-thirds of the distance from the anterior margin to the posterior 
furrow; thus showing a want of symmetry. 
In general aspect this spine is somewhat like Ph. arcuatus, McCoy," but 
is much broader and more compressed, and the ornamentation of the upper 
portion consists entirely of rows of distinctly separated stellate tubercles, 
rather than of pectinated ridges, as is the case with McCoy’s species. The 
most striking features in the fossil before us are the compressed form and 
the great breadth of base, by which it may be at once distinguished from 
all other described species. 
Formation and locality : Saint Louis limestone; Greencastle, Ind. 
ORTHOPLEURODUS CARBONARIUS, N. & W., sp. 
Plate XIX, Fig. 17. 
I have received from Mr, Alexander Butters, of Carlinville, Ill., a com- 
plete posterior tooth of this species, which has seemed worthy of representa- 
tion. It shows a beautifully punctate crown surface, having quite the form 
of those from which the original description was drawn, surrounded by a 
broad margin which was evidently overlapped by the integument. This 
specimen is comparatively thin, and the enamel crown has been indented 
probably in fossilization, proving that the base was soft, perhaps in part 
cartilaginous. The type specimens show only the crown, and are much 
thicker as well as larger. If to these were added broad, rough margins, 
such as are seen in the figure now given, we should have teeth two to three 
inches long and fully an inch in width at the widest part. 
' Brit. Pal. Fossils, 1854, p. 638, pl. 31, fig. 29. 
