18/6.] BLUE CROWS OF AMERICA. 269 



C. nana and C. pumilo, and partakes to some extent of the character 

 of both, in having the crescentic white frontal and superciliary marks 

 of the latter, and the throat coloured as in the former species. It is 

 probably the representative in Costa Rica of the Guatemalan C. pu- 

 milio and the Mexican C. nana. 



2. Cyanocitta beecheii (Vig.) : Scl. et Salv. Nomencl. p. 39. 



There are three somewhat similar species of Cyanocitta of a 

 uniform black below, two only of which are inserted in the list in 

 our ' Nomenclator ' under the names C. beecheii and C. crassirostris 

 These three birds may be readily distinguished as follows : — 



a. Frontis crista teuui elongata nigra 1. sanblasiana. 



b. Frontis plumis brevibus erectis, crista nulla. 



a'. Major : dorso lsete casruleo, naribus 



plumis frontalibus omnino tectis 2. beecheii. 



b'. Minor: dorso vmdi-cyaneo, naribus 



plumis frontalibus dimidio tectis 3. germana. 



The synonymy of these species should stand as follows . — 



Cyanocitta sanblasiana. 



Geai de San Bias, Neboux, Rev. Zool, 1840, pp. 290, 323. 



Pica sanblasiana, Lafr. Mag, de Zool. 1842, Ois. t. 28. 



Cyanocorax de San-Bias, Prev et Desmurs,Voy. ' Venus,' v. p. 200. 



Cissilopha sanblasiana, Bp. Consp. i. p. 380; Lawrence, Mem. 

 Boston Soc. N. H. ii. p. 284. 



" Cyanurus geoffroii, Bp." Gray, Hand-list, ii. p. 4, et in Mus. Brit. 



Hab. Western Mexico: San Bias (Nebonx) ; Acapulco (Leclan- 

 cher) ; Plains of Colima, Manzanilla Bay and Las Trochas (Xantus). 



Mas. S.G., Acad. Philad., Brit. 



Except as regards its thin frontal crest, this bird does not differ mate- 

 rially in form from its allies ; and we see no reason for making a genus 

 of it, as proposed by Bonaparte. The species is rare in European col- 

 lections. Messrs. Salvin and Godman's specimen is one of Xantus's 

 collection from the plains of Colima, and was presented to them by 

 the Smithsonian Institution. There is a single mounted example in 

 the Gallery of the British Museum, marked C. geoffroyi. In the 

 Jardin des Plantes there is also one mounted specimen of this species. 



It should be noticed that the figure of this bird in the ' Magasin 

 de Zoologie' gives the bill yellow, showing that in this species, as in 

 its two allies, this is a variable character, probably depending on 

 sex. 



californicus. Again, the type of Cyanurus, Sw., is not Gamdus cristatus, as given 

 in the above mentioned work, p. 271. This error was caused by Mr. G. R. Gray's 

 unauthorized assumption that the first species in any author's list must necessarily 

 be his type. But Swainson himself tells us that the first three species which he 

 mentions (i.e. C. cristatus, C. stelleri, and C. sordidus) are "aberrant," and that 

 the " typical" species are only found in the " tropics of America and India." 

 It is obvious therefore that Cyanurus, Sw. (1831)= Cyanocorax, Boie (1826), as 

 stated by Strickland I. s. c, and that Cyanocitta is the proper generic name for 

 the "Blue Jays " of America, as used by us in our " Nomenclator." 



