SYLVIIDiE. 45 



2. Cinclus ardesiacns. 



ardesiacus, Salv. Ibis, 1§67, p. 121, t. 2 ' ; Lawr. Ann. Lye. N. Y. ix. p. 92 ^ ; v. Frantz. 

 J. f. Orn. 1889, p. 290 \ 



Cinereus, subtus dilutior, capite toto fuscescente, gula albicantiore ; alls et cauda fusco-nigris, alarum tectri- 

 cibus et secundariis oinereo marginatis ; ciliis albis ; rostro nigro, pedibus flavis. Long, tota 5-5, alae 3'2, 

 caudse 1*6, tarsi 1*2, rostri a. rictu 0'9. (Desor. fern, ex Cordillera de Tole, in. statu Panamensi. Mus. 

 nostr.) 



S juv. corpora subtus albido, alarum teotrioibus albo termiuatis. (Descr. exempl. ex eodem loco. Mus. nostr.) 



Hah. Costa Eica, Dota Mountains (Z(?/e(?om ^ ^) ; Panama, Cordillera de Tole {Arci^). 



Of this southern form of Cinclus mexicanus but little is known. Since the receipt 

 of the two specimens from the Cordillera de Tole, which formed the basis of the 

 original description i, no others have reached us from that part of the country. It 

 has, however, been detected in Costa Rica in the Dota Mountains ^ ^ ; and Mr, Sclater 

 has a skin obtained in the same country. 



Cinclus ardesiacus is a close ally of C. mexicanus. It is, however, of a greyer tint ; 

 and though of smaller size, its bill fully equals that of its congener in length. The 

 legs, too, of the type specimen are yellow ; but this may indicate immaturity, as the 

 legs of young birds of C. mexicanus are described as of that colour. 



Pam. SYLVIID-a:. 



Subfam. SAXICOLINM. 



SIALIA. 



Sialia, Swainson, Zool. Journ. iii. p. 173 (1827). (Type Motacilla sialis, Linn.) 



This small genus of three species is a purely Nearctic one, two of its members passing, 

 however, beyond the southern boundary as far as Southern Mexico and Honduras. 

 Its relationship seems to be nearest to the Old-World genus Saodcola, from which it 

 chiefly differs in its much shorter tarsi and more thickened bill, besides possessing a 

 totally different character of coloration in the plumage. The young have a spotted 

 first plumage as in the typical Turdidse ; and with that family Sialia and, indeed, 

 Saxicola have a very close relationship. 



1. Sialia sialis. 



Motacilla sialis, Linn. Syst. Nat. i. p. 336 '. 



Sialia sialis, Baird, Rev. Am. B. i. p. 62' ; Baird, Brew. & Ridgw. N. Am. B. i. p. 62'; Coues, 



B. of the N.W. p. 13"; Sennett, Bull. Geol. & Geogr. Surv. iv. p. 6'; Merrill, Pr. U.S. 



Nat. Mus. i. p. 120"; Gundl. Orn. Cub. p. 61'. 



