182 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY III. 



ANALYSIS OF SPECIKS OF PAXTOSTEUS. 



•Scales very small, 100 to 1U3 iu the lateral line; 18 above and 10 below, iu a cross- 

 series : body elonj^ate, compressed, the caudal pedunelo contracted : head sboit, 

 wide, 5 iu length: muzzle obtuse, little projecting; ui)per lip wide; lower lip 

 full,emarj;inate ; jaws with wellduveloped cartilaginous sheaths : scales mueh 

 reduced in size forwards: dorsal rays 10 ; ventral 'J : color olive ; lower surface 

 yellow viKKSCENS, 3:j. 



•* Scales small, 80 to 85 in the course of the lateral line, 

 t Scales very much reduced and crowded anteriorly : upper lip full, pendent ; cartila- 

 ginous sheaths on jaws well developed, the commissure transverse and ab- 

 ruptly augulate at the corners of the mouth. 

 a. Body extremely elongate, the depth 5i to 7 in length : head 4J in length, short 

 and wide, with depressed and expanded muzzle, which considerably overhvings 

 the mouth : isthmus very wide : dorsal rays 11 ; ventral rays D : scales 15->JG-r2 : 



belly and lower tins yellowish, probably red in life platykiiyxchus, 39. 



aa. Body moderately elongate, the depth 4^ to 5 in the length : head rather short, 

 4J in length, not specially broadened; muzzle not greatly overhanging the 

 mouth : dorsal rays 9 (raiely 10) ; ventral rays 10 (rarely 9) : scales 11 to 14-83 

 to 87-13 to 15: light brown above, with dusky spots and clouds; males with 



the chin and fins red, and a crimson lateral b.ind gexkkosl's, 40. 



tt Scales subequal over the body, not much reduced forwards: upper lip rather nar- 

 row, not pendent ; cartilaginous sheath ou jaws obsolete (f). 

 h. Body comparatively stout, the caudal peduncle short and thick, the back some- 

 what arched, the depth 4i to 5 iu length : head short and wide, ilattish above, 

 4| to 5 iff length : scales 14-84-15 : dorsal rays 9 to 11 ; ventral rays 10 : black- 

 ish above, with one or two dark lateral shades pleueius, 41. 



38. PAXTOSTEUS VIRESCENS Cope. 



Gnoi Sitvkcr. 

 lQ7iJ—rantoHtiu8 rireaccns (Copk) Cope & Yakp.ow, Wheeler's Expl.W. 100th Mer. v, 

 Zool. G75. 

 raiitosteus virescens Jokd.vx «fc Copeland, Check List, 156, 1876. 



Habitat. — Arkansas River in Color.-vdo. 



Only a sin^^le specimen of this species is known, colletleil by Mr. V. 

 E. Aiken at riicblo, Colo. The small size of its scales indicates its 

 distinctness from the other si)ecies of Pautostcufi. The jjreenness of 

 coloration of the typical .'Specimen is probably due to its haviiijj been 

 ke[)t in a co[)per tanlc. 



^pecimetia in United i>late8 ynfional Museum. 



