48 TRIASSIC FISHES AND PLANTS. 
IscHYPTERUS MINUTUS, 0. Sp. 
Pl. XIII, Figs. 5, 5a. 
Fishes three inches in length by one inch broad ; long-ovoid in outline ; 
body widest at base of dorsal fin; head pointed, one-quarter the entire 
length ; dorsal fin located at about the center of the body, relatively large 
and broad; anal fin just reaching to base of caudal; tail narrow; caudal 
fin, like all the others, delicate in structure. 3‘ 
The little fishes upon which the above description is based have been 
found only at Durham, Conn. They differ from the other small species 
of the genus found elsewhere by their broader, more ovoid outline, the 
large size and breadth of the dorsal fin, and the general delicacy of 
structure. 
It is quite possible that we have here the young of some species of 
Ischypterus of which the mature form has been described under another 
name, but there is no fish found in the locality where these occur with 
which the resemblance is so close as to indicate this, and no connecting 
links have been found between these little fishes and those of larger size. 
Their structure was evidently very delicate, and they are so imperfectly 
preserved that a full description and satisfactory comparisons can not be 
made from any specimens yet obtained. Till more material further illumi- 
nating the subject shall be procured we may consider the individuals of 
this species as distinguished by their small size, ovoid form, delicate struct- 
ure, and especially by the relatively great size and breadth of the dorsal fin. 
The small size is in itself, perhaps, a sufficient reason for the delicate 
structure, which permitted the destruction of most parts; but it will be 
noticed that in both the specimens now figured the body is unusually wide 
opposite the dorsal fin, and this fin is relatively larger and broader than in 
any other known species of the genus. Possibly this is simply the result of 
immaturity, as the fins are abnormally large in many young fishes. The 
great breadth of the dorsal fin may, however, prove a constant character, 
and thus serve as a means of distinguishing the species. Small fishes occur 
at Boonton and Sunderland, but they are usually so badly preserved, that 
little can be said of their specific relations. Only at Durham do we find 
