FOSSIL FISHES. 61 
mark it as a member of the genus, although these raylets are fewer in number and of 
greater and more unequal length than in the other species. In the few specimens 
ebtained the caudal extremity is commonly found in a bent or half-twisted position. 
Found at Middlefield, Conn., Sunderland, Mass., and Boonton, N. J. 
In our excavations at Boonton, where we obtained several hundred 
fishes in better or worse condition, a few delicate, imperfect, and usually 
distorted specimens were found which correspond fairly well with the above 
description, and yet it has seemed to me that they are probably the young 
of the larger species of Catopterus; if not, the species can only be satisfac- 
torily defined from material more perfect than any I have yet seen. 
These little fishes are generally from two and a half to four inches in 
length and very imperfectly preserved; that is, the scales are scarcely visi- 
ble and all details of head structure are wanting. The fins, especially the 
caudal, are sometimes fairly well shown, and consist of numerous extremely 
fine parallel rays bordered by fulcra of corresponding delicacy. These 
prove that they belong to the genus Catopterus, but their minute size and 
their delicacy of structure are signs of immaturity, and it is therefore impos- 
sible to affirm that they constitute a distinct species. It may be said, how- 
ever, that with these little fishes somewhat larger ones are found which 
exhibit nearly equal delicacy of structure. They are from four to six inches 
in length, with a maximum width of perhaps an inch near the head. The 
fins are sometimes well shown, but the scales are almost invisible. Some- 
thing of their indistinctness may be due to decomposition or to imperfect 
fossilization, but the fin rays are much more slender than in the smaller 
individuals of Catopterus found at Durham, which I have designated by the 
name Catopterus minor. Hence I must conclude that they are not specifi- 
cally identical with these. For the present it may be perhaps as well to let 
these small, delicate, and imperfectly preserved specimens of Catopterus 
stand for Redfield’s species C. parvulus, but it is quite possible they will 
prove to be the young of C. gracilis. 
Genus DICTYOPYGE Egerton. 
Small heterocercal ganoids; body fusiform; head small, conical, one- 
fifth the entire length; muzzle rounded, obtuse; opercula large, semicireu- 
