176 University of California Ptihlications in Zoology. [Vol. 7 



ranges of auduhoni and coronata adjoin somewhere in that 

 general region. From a consideration of breeding ranges, 

 hybrids between the two might be expected. While presumably 

 distinct and well characterized species, coronata and auduhoni 

 are by no means distantly related, and there seems to be no 

 logical reason why the two should not cross occasionally. 



Nor are hybrids unknown within the Mniotiltidae. Helmin- 

 thophila lawrencei (Herrick) (see Ridgway, 1902, p. 452) is a 

 species described from probable hybrids between H. chrysoptera 

 (Linnaeus) and H. pi)ius C Linnaeus) ; and of another species 

 closely related to lawrencei, namely Helmiuthophila leucohron- 

 chialis (Brewster), Ridgway remarks {loc. cii., p. 453) that as in 

 lawrencei, certain of the characters of chrysoptera are combined 

 with certain others of piiuis. It is said that there is every proba- 

 bility that the four species, lawrencei, chrysoptera, pi)ii(s, and 

 leucohronchialis, interbreed freely to a large extent and are fertile 

 inter se, rendering the problem a very complicated one, since 

 dichromatism also may enter into it. A third described species 

 of Helmintlwphila, namely cincimiaiiensis (Langdon), is ad- 

 judged by Ridgway {loc. cit., p. 446) to be untenable on the 

 ground that it is clearly a hybrid between Helniinthophila pinus 

 and Oporornis formosa. 



As to the possibility of this individual being, not a hybrid, but 

 a mutant in the De Vriesian sense, or a germinal variant as de- 

 fined by Tower (1906), having sprung from one or the other of 

 the species auduhoni or coronata, it may be said that the hypoth- 

 esis of hybridization seems to be the one more nearly in accord- 

 ance with the facts of the case. If there were proved to be a 

 hiatus between the breeding ranges of the two species, the case 

 might be somewhat changed; but it is very probable that the 

 ranges overlap in the region suggested. If the bird is a mutant, 

 why should it, having sprung from one species, approach the 

 other in nearly all its characters? If the breeding ranges of the 

 two species do overlap, we might expect to find hybrids more 

 commonly. Evidently, however, crossing is infrequent, and not 

 at all comparable to that of the interbreeding of the flickers 

 [Colaptes cafer collaris and Colaptes auratus luteus). Scott 



