26 TRIASSIC FISHES AND PLANTS. 
The fin rays are few, broad, and undivided below in both; the anterior rays are 
characteristically strong; the fulera few, strong, acute, and closely appressed; 
in both a row of large, sometimes erect and pointed scales marks the line 
between the head and the dorsal fin. The obliquity of the posterior ex- 
tremity of the body is about the same; the mouth is small, the mandibles 
and maxillaries are weak, the premaxillaries united in a uniform arch, set 
with an even row of small, abruptly pointed teeth, as are also the max- 
illaries and mandibles; and the eye is placed above the posterior margin of 
the mouth. The divisions and the forms of the head plates are apparently 
the same, though I have not been able to verify by personal examination 
the descriptions of the head plates of Semionotus given by European authors. 
I can not, therefore, assert that Semionotus and Ischypterus should be united. 
I call attention, however, to the close, general, and special resemblances 
between them, and leave to those who may have better opportunities for 
studying the structure of Semionotus the decision of the question." 
The specific division of the great group of fishes representing the 
genus Ischypterus obtained from the Upper Triassic rocks of New Jersey 
and the Connecticut Valley is a matter of no little difficulty. The deserip- 
tions given by Mr. W. C Redfield in the article mentioned above are ex- 
ceedingly brief, and in the absence of the type specimens, which cannot 
now be certainly identified, it often becomes a matter of much doubt as to 
what were the fishes to which he applied these names. Only one has yet 
been figured, Ischypterus latus J. H. R., and this lacks both head and tail. 
In examining the collection of Triassic fishes left by Mr. W. C. Redfield, 
now at Yale College, and to which I have had access through the courtesy 
of Prof. O. C. Marsh, I found many without labels, and those which were 
named were in some cases so imperfectly preserved, that it was not easy to 
use them as guides in classifying the much larger number of specimens 
contained in the cabinet of Columbia College. 
‘Since the above notes were written two interesting papers have been published on the Triassic fishes 
of the Old World, viz, ‘‘On the Remains of Fishes from the Keuper of Warwick,” by E. T. Newton, 
Rev. P. B, Brodie, and Edward Wilson, Quar. Jour. Geol. Soc., August, 1887, and ‘On Two New Lepi- 
dotoid Ganoids from the Early Mesozoic Deposits of Orange Free State, South Africa,” by A. Smith 
Woodward, Quart. Jour. Geol, Soc. London, May, 1833. In both papers these fishes are described as 
species of Semionotus, which, if found in our Triassic rocks would be unhesitatingly referred to Ischyp- 
terns. 
