PLECTOSPONDYLI CYPEINIDAE H. IRIS. 653 



POGONICHTHYS, Gir. 

 POGONICHTHYS COMMUNIS, Gir. 

 Pogonichthys comnmnis, GIR., P. E. K. Eep., x, 247, pi. Iv. 



A variable species, heretofore recorded only from the tributaries of the 

 Missouri, but now obtained by Mr. Aiken in the upper waters of the Ar- 

 kansas. The grinding surface of the pharyngeal teeth is only well devel- 

 oped in adults ; in young up to four inches long it is often wanting ; num- 

 ber 4.2-2.4. Scales from | to f. 



HYPSILEPIS, Baird. 



HYPSILBPIS IEIS, Cope, ftp. MOW. 



PLATE XXXI, FIGS. 4, 4, 5, 5a. 



Dorsal fin above the ventrals ; teeth, 4-4, with masticatory surfaces 

 well developed ; anal radii, I. 9. 



This fish has the general characters of the species referred by Dr. 

 Girard to the genus Moniana, but differs in the replacement of the pectinate 

 edges of the pharyngeal teeth by grinding faces. It thus resembles the 

 Hypsilepides, with which it also agrees in the forms of the scales and the 

 coloration ; but no known species of Hypsilepis exhibits but a single row of 

 teeth. In H. anolostanus, there is but one of the lesser row, and it is certain 

 that the number of such may be irregular in the same genus. 



The present fish is, perhaps, the most brilliantly colored species of New 

 Mexico. Outline shortly fusiform ; body compressed ; head entering length 

 to basis of caudal three and three-fourths times ; the greatest depth entering 

 the same three and one-fourth times. Orbit entering length of head four 

 times ; interorbital width 15 times, and muzzle 0.8 time. Front and vertex 

 of males bearing dermal tubercles. Mouth oblique ; lips subequal ; maxil- 

 lary bone reaching line of orbit. Dorsal line well arched. Scales narrowly 



5 



exposed on the sides, S ; 17 rows in front of dorsal fin. Radii : D. I. 8 ; A. I. 



