62 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Adult male. — Length (skin), 134; wing, 116; tail, 56; exposed cul- 

 men, 8; width of bill at frontal antiee, 6; tarsus, 12; middle toe, 10/' 



Adult female.— lj(tngt\i (skins), 115-133 (124.7); wing, 100-111 

 (106.4); tail, 49-54 (51.4); exposed culmen, 6-7.5 (6.0); width of bill 

 at frontal antia?, 5-6 (5.8); tarsus, 11-12 (11.7); middle toe, 10-11 

 (10.6).* 



Southeastern Mexico, in States of Tabasco (Teapa), Yucatan (Chichen 

 Itza; Izalam; Calcehtok; Merida), and adjacent districts of Guatemala. 



Stelgidopteryx fulvipennis (not Cotyle fulmpennis Sclater) Lawkence, Ann. Lye. 



N. Y., ix, 1869, 200 (Merida, Yucatan). 

 SteJgidopteryx serripennis (not Hirundo serripennis Auduhon) Salvin and Godman, • 



Biol. Centr.-Am., Aves, i, 1883, 237, part (Merida, Yucatan). — Boucard, 



Proc. Zool. Soc. Lond., 1883, 442 (Yucatan). — SHAiiPE and WvArr, Mon. 



Hirund., 1894, 635, part (Yucatan).— Chapman, Bull. Am. Mus. N. H., viii, 



1896, 278 (Chichen Itza, Yucatan). 

 Stelgidopteri/.v ridgwayi Nelson, Proc. Biol. Soc. Wash., xiv, Sept. 25, 1901, 174 



(Chichen Itza, Yucatan; coll. U. S. Nat. Mus.). 



STELGIDOPTERYX SALVINI, new species. c 

 SALVIN'S ROUGH-WINGED SWALLOW, 



Similar to S. ser?'ipennis., but pileum distinctly darker than back, 

 tertials conspicuously margined with white, and chin and throat pale 

 cinnamon or cinnamon-buff. 



Adult male.— Length (skins), 113-120 (115.7); wing, 106-110 (108); 

 tail, ,48-52 (49. 4); exposed culmen, 6..5-7 (6.8); width of bill at frontal 

 antiffi, 5-6 (5.4); tarsus, 10-11 (10.1); middle toe, 10.'^ 



Southwestern Mexico (La Barca, Jalisco) and Guatemala (DueSas) to 

 Chiriqui (Divala). 



This form resembles S. ruficollis uropygialis in its pale cinnamon 

 chin and throat (though the color is hardly so deep), dusky pileum, 

 and whitish margins to tertials, but differs in having the rump con- 

 color with the back and in lacking any dusky spot at end of longest 

 under tail-coverts. Its characters are, therefore, intermediate between 

 those of S. serrijxmnis and S. Tiificollls uropygkdU; but since the 

 Mexican and Guatemalan specimens are precisely like two from Chiriqui 

 (Divala) and one from Costa Rica (Atiro), I believe it to be distinct 

 from both the forms named. A young bird (from Costa Rica), which 

 I take to be of this form, is indistinguishable from young examples of 

 8. serripennis and therefore very different from the corresponding age 

 of 8. ruficollis uropygialis. 



« Measurements of the type, no. 167947, coll. U. S. Nat. Mus. (Biol. Surv. coll.), 

 Chichen Itza, Yucatan, Jan. 29, 1901; Nelson and Goldman. 



^ Six specimens. 



"Type, No. 30716, coll. U. S. Nat. Mus., adult male, Duenas, Guatemala, Oct. 17, 

 1859; 0. Salvin. 



^ Four specimens. 



