GEOLOGICAL SUEVEY OF THE TERRITORIES. f)41 



A part of the operculum of a third individual (with similar spiues) 

 displays great rugosity and elevated radiatiug ridges ; length of articu- 

 lar cup, M. .0005. 



The specimens are chiefly from the Bad Lands of the Upper Green 

 Eiver. 



Ehineastes arcuatus. Cope, spec. nov. 



There are numerous spines about the size of those of the last species, 

 which differ in the want of the line serrated anterior edge. I select one 

 as the type, which belonged to the pectoral fin of the right side. It is 

 unbroken, and is curved from base to apex. The latter is acute by 

 an oblique posterior truncation. The surface is strongly striate, and 

 the teeth of the posterior edge are clovsely set ; the proximal point dis- 

 tally, the distal proximally. In this specimen there is a trace of 

 anterior serration ; in many specimens none whatever. The external 

 surfaces of the epiclavicular and coracoid bones are strongly rugose- 

 striate, as is the case in all the species of this genus, and the most 

 characteristic fragment is that portion of the scai)ular arch at the base 

 of the pectoral spine. 



M. 



Length of spine aa curve .*. 052 



Diameter at base, long OOG 



Diameter at base, short 004 



The recurved plate of the base is rugose, as in other cat-fishes. 

 Specimens generally from Upper Green Eiver. 

 The spiues are less compressed than la B. calvus. 



TUICROFILANES. Cope. 



Proceed. Amer. Philos. Soc., 1872, p. 479. 



Allied to Erismatopterus, Cope, and to the family of CyprinodonUdce. 

 Dorsal and anal fins short, eacli with a long and short si)inous ray on the 

 anterior margin. Yentrals beneath the dorsal. Operculum with a longi- 

 tudinal keel above. Mouth with a v\'ide gape, extending beyond orbit. 

 Scales wanting, represented by rigid fringes or hair like bodies. Several 

 important characters of this genus are not very distinctly displayed by 

 the specimen described. This is especially the case with the maxillary 

 region. Tiie premaxillar^- bone evidently forms a large part of the 

 arcade of the mouth, but whether the whole, is not certain. The pres- 

 ence of teeth and number of brauchiostegal radii cauqot be stated. 

 Ot!ier points, more definitely exhibited, are a preoperculum without 

 serrations, directed a little obliquely backward; a coracoid of little 

 width; an inferior postclavicle with a superior (proximcil) conchoidal ex- 

 l^ausion, and long, slender shaft, extending to the anterior extremity of 

 the femora. The latter are quite slender and acuminate anteriorly, 

 and grooved to the apex, but apparently not furcate. They do not 

 present any marked posterior union. Vertebrae not elongate. 



Caudal tin furcate. Interneural spines wanting in front of dorsal 

 fin ; those of the anterior rays very strong. Interhajmals of the ante- 

 rior anal rays similarly strong. Caudal iin embracing one vertebra, 

 and supported by separated hajmal spines. The characters which 

 separate Tricophanes from Erismatopterus are seen in the large mouth 

 and short iiuizzle aiid in the peculiar covering of the body. In the 

 former character it rese-mbles some of the Seapeli, while the latter 



41 as 



