296 FROCEEDINGS OF THE I^ATIOXAL MUSEUM. vol.52. 



obtained being supposed by Cope to be approximately equivalent to 

 the Amyzon beds. The specific characters are thus diagnosed by 

 the author: 



The mouth is small, and opens obliquely upward. Premaxillary and dentary 

 teeth in several rows. Size larger than that of the P. u-M(ei Cope, and the scales are 

 less numerous and of larger size. The spinous rays are less numerous than in that 

 species and the P. sexspinosus. Formula: D. XI. — ?; A. VII — ? 12; the soft anal 

 rays at least 12, possibly more. Scales in five or six rows above the vertebral column 

 and in 10 or 12 below it. Radiating ridges of proximal portion strong; disk and distal 

 portion scarcely roughened. Caudal vertebrae, 15. 



The specimens are all too much injiu-ed to permit of complete measurements. The 

 largest measures from the end of the muzzle to the base of the caudal fin 260 mm . , and 

 90 mm. in depth at the vertical fins. The last dorsal spine measiu-es 36 mm. A lateral 

 dorsal scale is 6 mm. in length. 



Family CICHLIDAE (Chromidae). 



Known in the fossil state by a single Eocene genus, the numerous 

 modern forms are tropical and subtropical fresh-water fishes. There 

 is no ingrowth from the suborbitals forming a suborbital shelf, no 

 supramaxilla, and a suture divides the lower pharpigeals. 



Genus PRISCACARA Cope. 



This, the only kno'^ii fossil genus, differs from all existing members 

 of the family in the possession of vomerine teeth. Small, conical 

 teeth are present along the margin in both jaws, and the preopercu- 

 lum is serrated. According to Haseman,^ there are six branchioste- 

 gal rays. 



Of the seven species which have been described by Cope from fresh- 

 water Tertiary formations in this country, the types of six are pre- 

 served in the United States National Museum. These species, ac- 

 cording to Cope, fall into two sections. "In the first," he writes, 

 "the ventral spine is very strong, and there are but 10 or 11 soft 

 dorsal radii: here belong P. serrata, P. cyplia, P. oxyprion, and P. 

 testudinaria. In the second, the first ventral spine is weak and slen- 

 der, and there are 13 or 14 radii of the second dorsal fin; in this divi- 

 sion belong P. Hops, P. pealei, and P. clivosa. 



^ PRISCACARA DARTONAE, new species. 



Plate 23. 



A species of large size, attaining a total length of 28 cm. to base of 

 caudal fin, in which the length of the head and opercular apparatus 

 is contained two and three-fourths tim.es. Maximum depth entering 

 into total length 2.7 times. Dorsal contour strongly arched and fron- 

 tal profile rising steeply to a point just in front of the origin of the dor- 

 sal fin; the vertebral column arched anteriorly so as to be directed 



1 Haseman, J. D. The relationship of the genus Priscacara. Bull. Amer. Mus. Nat. Hist., vol. 31, 1912, 

 pp. 97-101. 



