2(>1 G. F. Eaton — Collection of r Friassic Fishes at Yale. 



from the origin of that ray, and is about equal in length to 

 one-third the anterior margin of the fin. 



Pectoral tins show, on the superior surface, about 17 fulcra, 

 which are shorter than in S. fultus and other species (Plate 

 V, fig. 6). 



The last scale of the anterior dorsal ridge has its posterior 

 end slightly produced into a point (Plate Y, fig. 11). 



The best preserved specimens are a little more than three 

 times as long as deep, and have a more strongly convex outline 

 in the pectoral region than 8. fultus. 



In the majority of specimens, the flank scales, especially 

 those below the lateral line, show a tendency to become bi- 

 or tri-dentate on the postero-inferior angle (Plate V, figs. 7 

 and 8). Although this character is not always present, it may 

 serve to identify the species in question, when the dorsal and 

 pectoral fins are not preserved. No other species shows scales 

 thus strongly dentate. 



In reference to these dentate scales of S. micropte?nis, it 

 is interesting to note that a specimen of this species, showing 

 this character highly developed, but having the anterior dorsal 

 ridge (characteristic of the genus) concealed, was labeled by 

 Prof. Newberry " Catopterus Redfieldi." This error may have 

 been caused by the presence of the " one or more posterior 

 teeth " of the scales, given by Prof. Newberry as a character 

 of C. Medfieldi, and also by the form of the pectoral fin fulcra, 

 which offer a slight resemblance to those of Catoptemos. 



Semionotus Marshi W. C. Redfield. 



Ischypterus Marshii W. C. Kedfield, 1856, Proc. Am. Assoc. Adv. Sci. 

 (Name only). 



Ischypterus Marshii J. S. Newberry, 1888, Mon. U. S. Geol. Surv., No. xiv. 



The Redfield Collection contains an imperfect fish about 12 

 inches long, from Sunderland, Mass., bearing the name Ischyp- 

 terus Marshii. No description of this fish was published by 

 the Reclfields, although the name is found in a paper by W. C. 

 Redfield entitled " On the Relations of the Fossil Fishes of 

 the Sandstone of Connecticut, and other Atlantic States, to the 

 Liassic and Jurassic Periods" (Proc. Am. Assoc. Adv. Sci., 

 1856). Prof. Newberry's monograph contains a plate and a 

 description of this species, the credit for which is generously 

 given to W. C. Redfield. Three other specimens from. Sunder- 

 land, undoubtedly belonging to the same species as the above 

 mentioned fish, are in the collection of the American Museum 

 of Natural History in New York. According to the statement 

 of Prof. Whitfield of that museum, their labels, bearing the 

 name /. Agassizii, were written at the dictation of Prof. New- 

 berry, when the latter was asked to identify them. This 



