ART. 7 EEVISION OF THE GENUS BASILEUTEEUS — TODD 95 



Basileutcrus rufifrmi^ caudatus Nehlson, Proc. Biol. Soe. Washington, vol. 



13, 1899, p. 29 (near Alamos, Sonora, Mexico; orig. descr. ; type in coll. 



U. S. Nat. Mus.).— RiDGWAY, Bull. U. S. Nat. Mus., No. 50, vol. 2, 1902, 



p. 748 (descr.; range; refs.). 

 Basileutcrus rufifrou-s dufirsi Ridgway. Proc. U. P. Nat. Mus., vol. 15, 1892, 



p. 110, part (Sierra Madre near Mazatlan, Sinaloa) : Bull. U. S. Nat. 



Mus., No. 50, vol. 2, 1902, p. 747, part (Sinaloa localitie.s and refs.). 



Subspedfic characters. — Similar to Idiotes t^jifroTiS dugesi^ but 

 upper parts still duller (near citrine drab), and under parts averag- 

 ing slightly paler. 



MeaMirenients. — Male: Wing. 50-55 (average, 52.5); tail, 55-61 

 (58.5): bill, 8.5-9.5 (9); tarsus, 19.5-21.5 (20.5). Female: Wing, 

 48-52 (50.5); tail, 53-60 (56.5); bill, 8.5-9.5 (9); tarsus, 20-21 

 (20.5). 



Range. — Northwestern Mexico, in States of Sonora, Chihuahua, 

 and Sinaloa. 



Remarks. — This race is easily told from /. rufifron^ mififrons^ but 

 is so close to /. ru-flfrons dugesi as to be distinguishable only in series 

 of specimens comparable for season. It is the palest form of the 

 s<pecies, reflecting the aridity of its habitat. A juvenai example (No. 

 21,766. collection William Brewster, Bravo, Chihuahua, July 23, 

 1888) is very much paler above than the corresponding stage of /. 

 rufifrons jouyi. 



Specimens from Sinaloa are in my opinion better referred here 

 than to /. j'ujifrons dugesi. The greater length of the tail, supposed 

 by Messrs. Nelson and Ridgway to be diagnostic of this race, is in- 

 considerable ; in fact, comparative measurements of all the forms of 

 the r-uffroiis group of conspecies vary little among themselves. 



SpeciTnens examined. — Mexico: Mina Abundancia, Chihuahua, 11; 

 Hacienda de San Rafael. Chihuahua. 10; Carmen, Chihuahua, 4; 

 Jesus Maria, Chihuahua, 4; Bravo, Chihuahua, 8; near Batopilas, 

 Chihuahua, 1; Colonia Garcia (15 miles west of Chihuahua), Chi- 

 huahua, 1; near Oposura, Sonora, 4; Alamos, Sonora, 5 (including 

 type); Nopalera. Sonora, 1; Plomosas, Sinaloa. 3; Sierra Madre, 

 near Mazatlan, Sinaloa, 1. Total, 53. 



o 



