NOTICE OF INTERESTING NEW FORMS OF 
CARBONIFEROUS FISH REMAINS. 
C. R. EASTMAN. 
TuRoucH the kindness of Professor G. Hambach, of Wash- 
ington University, St. Louis, a number of highly instructive 
Carboniferous fish remains have recently been brought to the 
writer's attention, two of which seem to possess considerable 
interest, and are therefore made the subject of the following 
notice. The first to which attention is invited is a remarkable 
specimen of Erismacanthus from the vicinity of St. Louis, now 
preserved in the private collection of Dr. Hambach. It is 
unquestionably the largest and at the same time most perfect 
spine belonging to this genus yet brought to light, and appears 
to be distinct from other described species. The second speci- 
men noticed in the present paper yields new information regard- 
ing the dentition of Campodus corrugatus, and is from the Coal 
Measures of Winchester, Illinois. 
Genus Erismacanthus M'Coy. 
The two European and one American species of this genus 
that have been described are evidently closely related to Physo- 
nemus, but differ in that the spines are divaricated, the two 
branches extending in opposite directions in the same vertical 
plane. The imperfect ichthyodorulites known as Gampsacan- 
thus, Lecracanthus, and Dipriacanthus are also of the same 
general nature, and all these bodies are interpreted by most 
authors as lateral head spines of presumably cochliodont or 
petalodont sharks. The occurrence of spines on either side of 
the head in sharks and chimæroids has been observed in a 
number of forms, such as in Ovacanthus armigerus Traquair, 
from the Calciferous sandstone of Eskdale, Scotland, in the Per- 
mian JZezaspis armata, and in Mesozoic cestracionts (Hybodus). 
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