572 



U. S. p. R. R EXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 



Detailed measurements. 



lAst of specimens. 



PICICORVUS, Bonaparte. 



Picicorvus, Bokaparte, Consp. Av. 1850, 384. Type Corvus columbianus, Wils. 



Cu. — Lead color, with black wings and tail. Bill longer than the head, considerably longer than the tarsus, attenuated, 

 slightly decurved ; tip witliout notch. Culnien and commissure curved ; gonys straight or slightly concave, as long as the tarsi. 

 Nostrils circular, completely covered by a full tufl of incumbent wliile bristly feathers. Tail much' shorter than the wings, 

 nearly even or slightly rounded. Wings pointed, reaching to the lip of till. Third, fourth, and fifth quills longest. Tarsi 

 Bhort, scarcely longer than the middle toe, the hind toe and claw very large, reaching nearly to the middle of the middle claw, 

 the lateral toe little shorter. A row of small scales on the middle of the sides of tarsus. 



Without a specimen oi Nucifraga conveniently at hand I cannot express exactly the difference 

 between it and the present genus. Judging from descriptions, however, the hill is more 

 curved, the culmen heing decidedly convex ; the nasal feathers are longer ; the wings extending 

 only to the middle of the tail, instead of near the tip. The very long wings distinguish it from 

 all other American genera, except Corvus, which has a much thicker hill, &c., and is entirely 

 black. The short tarsi and lengthened lateral and hiud.er toes are (;[ulte remarkable. The hind 

 claw is rather longer than its digit. The sides of the tarsi exhibit the row of small scales seen 

 in Corvus. The commissure is considerably curved, more convex than the culmen, which bends 

 very gently throughout from the very base. There is a geaeral approximation to the Slurnella- 

 like bill more decidedly visible in Gymnokitla. The nostrils are small, with the anterior portion 

 less deeply bevelled off than in Corvus. 



