1903.] Hay, North American Cretaceous Fishes. 9 



guished from the corresponding part of P. pcrniciosa. In- 

 deed, this part is probably much the same in all the species. 



Impelled by the evidences furnished by the materials before 

 me, I am compelled to regard Cope's Erisichthe nitida, E. 

 penetrans, and Pelecopterus chirurgns, and Loomis's P. obli- 

 quidens as belonging to a single species, to which the name 

 Protosphyrcena nitida must be applied. 



Protosphyraena pemiciosa {Cope). 

 Plate I, Fig. i. 



Ichthyodectes perniciosus Cope (E. D.), Bull. U. S. Geol. and Geog, 

 Surv. Terrs. I, No. 2, 1874, p. 41; Vert. Cret. Form. West, 1875, 

 P- 275- 



Pelecopterus perniciosus Cope (E. D.), Vert. Cret. Form. West, 1875, 

 pp. 244D, 273, pi. xlviii, fig. 2; pi. Hi, fig. 2. 



Protosphyrcena pemiciosa Woodward (A. S.), Cat. Foss. Fishes Brit. 

 Mus. Ill, 1895, p. 414. — ? LooMis (F. B.), Palaeontogr. XLVI, 

 1900, p. 221, text fig. 2. — Hay (O. P.), Bibliog. and Cat. Foss. 

 Vert. N. A. 1902, p. 379. 



This species was established in 1874, as cited, on a frag- 

 ment of a fin which was afterwards figured on Plate lii of 

 Cope's ' Vertebrata of the Cretaceous Formations of the West.' 

 In this work there were figured also two other fragments of 

 fins which were referred to this species. Of these the one 

 which furnished Fig. 2 of Plate xlviii quite certainly belongs 

 to P. pemiciosa; the one which is represented by Fig. 13, 

 Plate xliv, appears to belong with those fins which have been 

 referred to P. tenuis. It will be observed that the undula- 

 tions of the edge of this specimen, instead of increasing in 

 height from the base toward the tip, seem to be subsiding. 



In the Cope Collection of fishes and reptiles are fragments 

 of several pectoral fins of P. pcrniciosa; but one specimen is 

 especially worthy of description and illustration. This bears 

 the Museum's number 1901. The record accompanying the 

 specimen shows that it was collected by Mr. R. Hill, in 1877, 

 in the Niobrara beds along the South Fork of Solomon River, 

 Kansas. The shoulder girdle accompanies the fin. 



The present length of the fin blade (PI. I, Fig. t) is 838 mm., 

 but it has doubtless been originally somewhat longer. It is 



