NORTHWESTERN MEXICO. 285 



In the different collections there are seventeen specimens, all purporting to be this spe- 

 cies ; nine of them are fully adult ; in these the long central crest feathers are black, with 

 ,their ends just tinged with blue ; six of the others have the crest feathers ending with 

 white ; one of these specimens is younger, it has the chin black, the throat bluish-white, 

 surrounded with black; this seems to be the stage of plumage on which Dr. Finsch, I. c, 

 founded his new species, G. elegans. The other two are nearly adult, and in fine plumage, 

 the ends of the crest feathers blue, just tipped with bluish-white. It appears therefore 

 that the long crest feathers are tipped with white in the younger birds, and that this color 

 is gradually replaced by blue in the adult. The markiags, also, on the ends of the shorter 

 crest feathers differ in the various specimens, showing a transition from white to blue. 

 There appears to be some irregularity in acquiring the fully mature plumage ; in some the 

 throat is entirely black, while the crest feathers are stUl tipped with white ; in others the 

 white has entirely disappeared from the crest feathers, and the throat feathers have their 

 ends bltdsh-white, retaining on that part the plumage of the immature bird. 



Mr. Salvin suggests that the difference of plumage between C. colliei and the 0. elegans 

 of Dr. Finsch, may be sexual. But, as stated by Col. Grayson, the sexes do not differ in 

 plumage ; this is also shown by the examples, there being old and young of both sexes in 

 which the plumage is the same. 



I much fear that the species of my friend Dr. Finsch cannot be sustained, and had he the 

 same evidence before him that I have, he would doubtless come to the same conclusion. 



107. Calocitta formosa (Sw.). 

 Manzanilla Bay, Rio de la Ameria, Xantus. 



108. Xanthoura luxuosa (Less.). 

 Sierra Madre, Xantus. 



Fam. Dendeocolaptid^. 



109. Dendrornis mentalis Baird. 



" " Ann. Lye, N. Y., viii., p. 481. 



Mazatlan, Grayson, Xantus, Bischoff; Tepic, Xantus. 



Fam. Tteannid^. 



110. Attila cinnamomeus Lawr. 



" " Ann. Lye, N. Y., x., p. 8. 



Mazatlan, Grayson. 



" Not a common species, found in this locality the entire year, inhabits the thick woods ; I also found it in 

 the State of Jalisco, near Tepic. It feeds upon the various kinds of wasps and bees ; the stout and numerous 

 rictal bristles are well arranged to protect it from their sting. The singular form of the bill is a distinguishing 

 feature in this species ; it has the appearance of being slightly curved upwards to near the tip, which is bent 

 downwards in a very acute point, the culmen very prominent, the under mandible curved upwards, commis- 

 sure nearly straight, bill notched at point." 



111. Sayornis nigricans (Sw.). 

 Mazatlan, Grayson. 



IIEItCOIBS BOST. aOC. NAT. HIST. VOL. n. 72 



