164 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



bones. The mandibular ramus is very deep at the coronoid region, and if tlie fissures are not 

 fnictures, the angular bone is distinct. The frontal bones are extended well forward to a point 

 above the mouth. The probable ethmoid in front of them is short and wide. The frontals ex- 

 tend also well posteriorly, meeting the snpraoccipital. The superior face of the latter is rather 

 large and is subtriangular in outline and has a produced nuchal crest. The Intercalaries each 

 present a sharp angle posteriorly. The branchiostegal rays are robust. No entire vertebra in- 

 cluded in the caudal fin, but the usual modified one. 



Char, specif. — The general form is elongate, and the head is short. The dorsal and ventral 

 fins, which are opiiosite each otiier, are posterior in position, while the short anal is not far removed 

 from the caudal. The lobes of the latter are long and divergent. The muzzle overhangs the mouth 

 a little, but the latter is so short that the end of the piemaxillary bone only reaches half way to 

 the anterior boiderof the orbit. The operculum is convex downwards and jiosteriorly. The 

 length of the head enters the length with the caudal fin six and a half times; and the greatest 

 dei)tli, which is in front of the dorsal fin, enters the same six and three-quarters times. Vertebrae: 

 abdominal, 3-1; caudal, 14.J. Radii: Br. Ill or IV,robust; D. I (very short), 12; A. II (very small), S; 

 V. (very small), G or 7; P., not countable. The scales are of medium size, five longitudinal series 

 in a centimeter anterior to the ventral fin. Their surface is sculptured by longitudinal, parallel, 

 fine, sharp grooves of .03""" in width. The fringe on the free edge of the scale is composed of 

 flat, acute, and rather long, closely-set spines. 



Measurements. 



Total length 485 



Length to base of caudal fin 395 



Length to line of aual 332 



Length to Hue of dorsal 224 



Length of head 081 



Length of gape of mouth 015 



Width of skull at orbits 019 



Width of skull at pterotics 030 



Depth at front of dorsal fin 070 



Depth at front of anal fin 050 



From Twin Creek, Wyoming Territory. 



PEISCACARA HYPSAOANTHTJS sp. nov. 



The specimens of this species which have come under my observation are the smallest of the 

 genus, and I have therefore questioned their maturity. They have, however, all the characters of 

 adults, and as I have now seen a number of specimens which agree in various peculiarities as well 

 as in size, I am satisfied as to their representing a species which has not as yet been recorded. 



The Priscacara hypsacanthits belongs to the section of the genus with a small number of soft 

 dorsal rays, and with robust ventral spine. It difiers from all the species in the length of its 

 slender dorsal spines, especially the fourth, fifth, and sixth. The superior outline of the head and 

 body are but little arched from a straight line. The form is moderately robust. The scales are 

 small. Length of head equal to greatest depth, i. e., at front of dorsal fin, and entering length 

 with caudal fin, 3.4 times. Orbit large, entering length of head four and one-half times. The 

 origin of the dorsal fin is a little anterior to that of the ventral. Its superior outline is notched 

 to two-fifths the length of the spine of the second dorsal. The border of the caudal fin is a little 

 concave. The first anal spine originates below the third soft ray of the dorsal, and the soft rays 

 of the ventral reach the same point. Vertebrae: Abd. X; caud. XIV. Rays: Br. VII; D. X, 9; the 

 last soft ray split into two: A. Ill, 9. Scales in eight rows in an oblique band from the last soft 

 ray of the anal fin to the vertebral column. Total length, M. .002; to base of caudal fin, .019; to 

 line of first aual ray, 0.33; to line of base of ventral, .023; of head, .0108; depth at ventral fin, 

 .010 ; at last ray of dorsal, .011 ; at base of caudal, .007. The specimens are from Twin Creek, 

 Wyoming Territory. 



Besides other peculiarities, the presence of an elongate spinous ray at the front of the second 



