46 STLVIID^. 



Sialia wilsoni, Sw. Zool. Journ. iii. p. 173'; Scl. P. Z. S. 1856, p. 293', 1858, p. 299", 1859, 

 pp. 361", 371'' ; Scl. & Salv. Ibis, 1859, p. 8 ", 1860, p. 29'* ; Jones, Nat. Bermuda, pp. 28, 

 66"; Taylor, Ibis, 1860, p. 110"; Owen, Ibis, 1861, p. 60". 



Sialia azurea?, Sw. Phil. Mag. new ser. i. p. 369 (descr. nulla!)''; Baird, Rev. Am. B. p. 62"; 

 Sumichrast, Mem. Bost. Soc. N. H. i. p. 544'°. 



Supra azurea, uropygio paulo tetiore, genis vix obscurioribus ; subtus rufo-castanea, ventre medio et crisso 

 albis. Long, tota 6-5, ate 4-1, caudse 2-8, rostri a rictu 075, tarsi 0-75. (Descr. maris ex Volcan de Agua, 

 Guatemala. Mus. nostr.) 



Juv. supra fusca, interscapulio albo guttato ; subtus albescens, plumis (prajcipue in pectore) rufo marginatis, alis 

 et Cauda cseruleseentibus. (Descr. av. juv. ex Duenas, Guatemala. Mus. nostr.) 



Hab. Eastern United States, west to Fort Laramie, north to Lake Winnipeg 3. — 

 Mexico, Eeal del Monte {BuUocJc^^), Cordova and Cerro del Gallego {SalW), 

 valley of Mexico [le Strange), temperate region of Vera Cruz {Sumichrast ^'^^ 

 Jalapa {de Oca^^), Mirador {Sartorius^), La. Parada^o and Juquila^^ {Boucard); 

 Guatemala, Quezaltenango, ridge above Totonicapam, Godines, Duenas ^^ San 

 Geronimo", Tactic, Coban^* (C>. S.&F. B. G.); Hondubas {Taylor '«).— Bbkmuda i^- 

 Cuba 7. 



The common Bluebird of the Eastern States, which has been known to naturalists 

 since the days of Catesby *, was described by Linnaeus under the name Motacilla sialis ; 

 but Swainson, using Sialia for the generic name, proposed to call the bird ^S*. wilsoni, 

 by which it was long known. Prof. Baird restored the Linnsean specific name whilst still 

 retaining Swainson's generic title, considering that the slight difference in the termi- 

 nation of the two words was sufiicient to justify such a course. The bird is now 

 universally known as Sialia sialis by all American ornithologists ; and we follow their 

 practice. 



In his ' Synopsis of the Birds of Mexico ' ^^ Swainson seemed to consider the Mexican 

 bird to be distinct from the northern one, and proposed for it the name Sialia azurea, 

 but gave no description of it. This name Prof. Baird ^^ adopted for the Mexican 

 and Guatemalan bird, believing it to possess characters sufl&ciently pronounced to 

 admit of its being considered distinct. We have carefully examined a number of 

 specimens, to ascertain whether S. azurea can be distinguished with certainty; but 

 we fail to find constant characters by which to define it. Some Guatemalan examples 

 have the chestnut colour more diffused over the under surface and are somewhat large ; 

 but scarcely any difference is to be seen in the colour of the back when compared 

 with specimens of true ^S*. sialis ; and the other points being variable, we doubt whether 

 S. azurea deserves specific rank or is even to be considered a local form. 



S. sialis would appear to be a common bird in Mexico, though by no means so 

 abundant in Texas ^ ^. In the State of Vera Cruz Prof. Sumichrast considers it to be 

 unquestionably a resident, but not always found in the same localities ; wherever it 



* Nat. Hist. Carol, i. p. 47, t. 47. 



