NO. 2177. FOSSIL FISHES IN NATION A.L MUSEUM— EASTMAN. 297 



nearly parallel to the dorsal contour. Spinous rays of all the fins 

 relatively weaker than in other knoMTi species, those of the dorsal fin 

 not quite equalling the soft rays in length; pectoral fin rays when 

 appressed against the ventral margin reaching to the anal; the latter 

 having the second and third spines about equally developed. Ver- 

 tebrae: 10 abdominal, and 15 caudal. Radial formula: 



D. XI.-ll; A. III. -8; V. 1-5. 



The holotype upon which this species is founded is a large (35 cm. 

 long) and handsome specimen, excellently preserved, and remarkable 

 for its steep facial profile and correspondingly increased depth of body 

 as compared with other species. The vertebral column is also prom- 

 inently flexed anteriorly, and the number of vertebrae is greater than 

 in related species. The number of spinous rays in the dorsal fin is 

 also greater by one than in either P. serrata or P. oxyprion, and the 

 the number of rays in the anal fin the same as in these species. The 

 spinous rays of all the fins are less robust than in any described species, 

 and those of the dorsal fin are relatively shorter. In form, of body 

 this species stands m rather close agreement with P. clivosa Cope, 

 which is smaller, and differs m fin characters and number of vertebrae. 

 In other respects the new species shows considerable resemblance to 

 P. oxyprion, in particular the number of anal and pelvic fin-rays being 

 the same. One may say that it is intermediate in respect to the ma- 

 jority of its characters between these two species, P. oxyprion and P. 

 clivosa; and although attammg as large a size as the type-species, P. 

 serrata, it is much less formidably armed. ^ Correlating with a weaker 

 defense, it was probably of less active habits. 



The writer takes pleasure in naming this species in honor of his 

 friend, Mrs. N. H. Darton, of Washington, who with her husband has 

 collected fish remains from western Tertiary horizons. (Cat. No. 2381, 

 U. S. N. M.) To Mr. Darton the writer is indebted for the opportunity 

 of studymg the remams collected from near Hazen, Nevada (see p. 

 291, under Parafundulus) and from the Black Hills uplift of *South 

 Dakota. 



Formation and locality. — Green River Eocene, near Fossil, Wyoming. 



UNCERTAIN PLACE. 



Genus ISCHYRHIZA Leidy. 



The peculiar teeth first described by Leidy from the Cretaceous of 

 New Jersey under this name, and since found in the Eocene of the 

 Atlantic Coast region and in the Fox HiUs Cretaceous of New Mexico, 

 were conjectured by Cope to have belonged to teleost fishes, allied to 

 the Esocidae. He also proposed that certain coalesced caudal ver- 

 tebrae ("hypural fans") accompanying the Cretaceous teeth and 

 occurring also m the Eocene of Maryland and South Carolina, should 



