2. COLAPTES. 23 



The most remarkable feature in connection with the Picidas of 

 North America is the iutcrhreeding between C. auratus and 

 C. mexicanus, resulting in a race frequently called Injhridus, which 

 occupies a district rarely invaded by pure-blooded birds of either 

 of the parent species, and but rarely found out of that district. The 

 very existence of this race, occupying as it does a distinct region, 

 seems to point to the conclusion that the birds are fertile, otherwise 

 it would cease to exist, and hybrids would only be found where the 

 opposite species came in direct contact. A proof of the fertility of 

 G. ayresi is given by Audubon, who states that in the nest-hole of 

 the type-specimens there were sis young birds. The breed may be 

 one of long standing, but that it is replenished by pure blood from 

 without seems highly probable, and may account for the violent 

 contrast sometimes produced in the two sides of the same bird, 

 which I think would not result in a race if left entirely to them- 

 selves, as the tendency would be towards the acquirement of a fixed 

 character. The name of hyhrklus is untenable. A hybrid or 

 simple cross between two species can have no specific name, and it 

 is only upon the assumption that the birds resulting from this cross 

 are fertile, and are producing a race having the characters of both 

 parent forms (although irregular in their distribution and develop- 

 ment), that they can have a name bestowed upon them, and, if such 

 be the case, I see no other title for them than that of C. ayresi of 

 Audubon. The name given by this author must therefore be 

 understood to apply to the race produced originally by the union of 

 C. atiratns and C. mexicanus, and possessing such varied characters 

 as to render description vague and indefinite, but evidently sugges- 

 tive of very close interbreeding, and not as tending to show that all 

 the individuals comprising the race are the immediate descendants 

 of true C. auratus and C. mexicanus. There can be no doubt that 

 C. auratus also interbreeds with C. chrysoides, but I do not see how 

 any specific title can be applied to these hybrids, which occupy no 

 distinct region. 



Hah. Upper Missouri and Yellowstone Rivers, and the Black 

 Hills ; occasionally ranging into British CJolumbia and California. 



a. cT ad. sk. British Columbia. J. K. Lord, E^q. [P.]. 



b. 2 ad. sk. California. Tweeddale Coll. 



e. (j ad. sk. San Francisco (Hensh. Coll.). Salviu-Godman Coll. 



d. J ad. sk. Stockton, California (Beldbi(f). Salviu-(Todnian Cdll. 



e. cJ ad. sk. Puebla, Colorado, Nov. {Hensh. Salvin-Godmau Coll. 



Cull.). 



8. Colaptes campestris. 



Carpintevo campestre, Azara, Apunt. ii. p. 303 (180-5). 

 ricus campestris, Viedl. N. Diet. d'Hist. Ned. xxvi. p. 101 (1818) ; 

 Licht. Verz. Doidd. p. 10 (1823) ; »S>j!',r, At. Bras. i. p. 57, 



Pi . _ . ____.,._.., ^ ,..„,. 



Chrysoptilus campestris, Sivains. Chissif. B. ii. p. 308 (1837) ; Gould, 

 in Danvins Voy. Beag., Bds. p. 113 (1841) ; Hartl. Ind. Azara, 



