PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 11 



legs, and feet, black; iris "gray," "light olive," or "yellow" (Sumi- 

 CHRAST, MS.). Wing 4.30-4.50 (4.40), tail 4.90-5.20 (5.02), culmen .G5- 

 .67 (.06), tarsus 1.20-1.35 (1.27), middle toe ,80-.85 (.82). 



Rah. — Istliuius of Tebuantepec (Tehuantepec City: F. Sumicbrast). 



Types in U. S. Nat. Miis. (N^os. 50678, <?, and 59677, 9, Tebuantepec 

 City, October 8 and 29, 1869: F. Sumicbrast). 



The bird described above is a well-marked race, apparently referable 

 to M. (/ilvus, tbougb ijossibly (witb M. gracilis, Cabanis, of Yucatan, 

 Guatemala, and Honduras) distinct speciiically. A considerable number 

 of specimens of the various forms referred by authors to M. gilvus, rep- 

 resenting many localities, have been examined in this connection, and the 

 result appears to justify the subdivision of that species into several 



A. Whitish superciliary stripe very distinct. 



a. gilvus. Above dark brownish gray, general outer surface of the 

 wings not distinctly darker. Wing 3.85-4.40 (4.08), tail 

 3.90-5.00 (4.39), culmen .70-.80 (.73), tarsus 1.18-1.32 (1.27), 

 middle toe .80-.90 (.83). H«&.— Guiana, Tobago, Grenada, 

 Sta. Lucia, St. Vincent, and Martini<iue.* (10 specimens exam- 

 ined.) 



/?. melanopterus. Above much lighter gray, the wings distinctly 

 darker, by reason of narrower iialer edgings. Wing 4 60-4.75, 

 (4.67), tail 4.80-5.30 (5.12), culmen .72-.80 (.77), tarsus 1.35- 

 1.38 (1.30), middle toe .88-1.00 (.92). iTflft.— Venezuela and 

 Colombia. (4 specimens.) 



B. Superciliary stripe very indistinct. 



y. gracilis. Above deep gray (about intermediate in shade betAveeu 

 gilvus and melanopterus), the wings pure black, in abrupt and 

 very conspicuous contrast, and with the clear white markings 

 very sharply defined. Wing 4.15-4.80 (4.49), tail 5.00-5.80 

 (5.38), culmen .70-.75 (.72), tarsus 1.20-1.37 (1.31), middle toe 

 .80-.90 (.87). Hah. — Guatemala, Honduras, and Yucatan. (5 

 specimens. 



8, lawrencei. Above decidedly brownish gray, the wings about as 

 in M. melanopterus. Wing 4.30-4.50 (4.40), tail 4.90-5.20 (5.02), 

 culmen .65-.67 (.66), tarsus 1.20-1.35 (1.27), middle toe .80- .85 

 (.82). Hah. — Southern Mexico (Isthmus of Tehuantepec). (3 

 specimens.) 

 The synonymy of the several forms is as follows : 



a. Gilvus. 



Turdas gilvus Vieill. Ois. Am. Sept. ii, 1807, 15, pi. 68 bis (Gniana) ; Nouv. Diet. 

 XX, 1818, 296 ; Enc. M6th. 1823, 678. 



*A very young bird, unquestionably of this species collected by Ober (Nat. Mus., 

 No. 75125 ; orig. No. 793 ; "August"). 



