752 THE AMYZON BEDS. 



PERCOMOKPHI. 

 TRICHOPHANES Cope. 



Proceed. Amer. Philos. Soc, 1872, p. 479 (July 29). Annual Report U. S. Geol. Surv. Terrs., 1872 (1873), 



p. 641. 



The pvemaxillary bone forms all or nearly all of the superior arcade of 

 the mouth. There are a few rows of small equal teeth en brosse on the 

 dentary bone. Four rather wide branchiostegal rays are visible in the 

 specimen. The posterior superior angle of the operculum (which is dis- 

 placed in the specimen) is drawn out into an acute short spine ; otherwise 

 the bones of the head are smooth. There is a row of small teeth en brosse 

 probably on the palatine or pterygoid bone. The anterior vertebrae are 

 unmodified, and the centra are not elongate. A strong acute spine supports 

 the dorsal fin, and a similar one the anal fin, in front. There is an elongate 

 postclavicle on each side, which extends parallel with the femur to the base 

 of the ventral fin. The femur is divided ; the external portion is straight, 

 and extends to the clavicle, while the other portion is curved inward and 

 forward, reaching the apex of the corresponding bone of the opposite side. 

 Ventral radii, 8. The dorsal originates above the ventral fin. The scales 

 are peculiar, and characteristic of the genus. They are very thin, and with- 

 out or with minute sculpture. Their borders are fringed with long, closely- 

 set, bristle-like processes, which correspond to the teeth of the ctenoid scale. 



This genus, Amphiplaga, and JErismatopteriis form a group which prob- 

 ably belongs to ihe family of Aphrodediridce, which is represented in modern 

 American waters. T. foliantm, the only one in which the parts are large 

 enough and suflSciently well preserved for observation, exhibits the furcate 

 character of the femora which characterizes the family in question among 

 Physoclystous fishes. 



The first described species is the T. hians, from Osino, Nevada ; the 

 T. foUarmn and T. copei are from the South Park of Colorado. I do not 

 possess a specimen of the last named, which was described by the Princeton 

 paleontologists.^ It differs from the T. foliarum in its smaller scales. 



'Pal. Keport Princeton Sci. Expeflition, I, 1878, p. 93. 



