PICOLAPTES. 185 
these, P. lewcogaster is peculiar to the uplands of Mexico, P. gracilis to Costa Rica. 
Of the other two, P. affinis and P. compressus range nearly over the whole area-—the 
former in the highlands, the latter in the lowlands of the same countries. 
1. Picolaptes leucogaster. 
Xiphorhynchus leucogaster, Sw. Phil. Mag. new ser. i. p. 440°. 
Picolaptes leucogaster, Lafr. Rev. Zool. 1850, p. 150°; Scl. P.Z.S. 1858, p. 297°; Cat. Birds Brit. 
Mus. xv. p. 147*; Sumichrast, La Nat. v. p. 248°. 
Thripobrotus leucogaster, Cab. & Heine, Mus. Hein. ii. p. 37°. 
Picolaptes atripes, Hyton, Contr. Orn. 1851, p. 767; 1852, p. 22°. 
Supra olivaceo-brunneus, capite summo nigro, plumis macula discali pallide cervina, cervice postica quoque 
striis cervinis nigro utrinque limbatis notata; dorso postico, alis extus et cauda rubiginosis, tectricibus 
alarum dorso concoloribus: subtus gula alba, plumis corporis reliquis macula magna elongata discali 
albida utrinque nigro limbata ornatis, tectricibus subcaudalibus medialiter striatis, subalaribus fulvis 
remigibus cinnamomeis fusco terminatis: rostro corneo, pedibus plumbeis. Long. tota 9:0, ale 4:8, 
caudze 3°9, rostri a rictu 1°55, tarsi 0°8. (Descr. maris ex Rio Frio Ixtaccihuatl, Mexico. Mus. nostr.) 
@ mari similis. 
Hab. Mexico, Nuri in Sonora (W. Lloyd), Ciudad in Durango (A. Forrer*), Sierra de 
San Luis Potosi, Sierra de Bolafios, Sierra de Nayarit, Sierra Nevada de Colima, 
Tenango del Valle, Rio Frio Ixtaccihuatl in Puebla (W. B. Richardson), Temas- 
caltepec (Bullock +), San Salvador el Verde in Puebla (Ff. Ferrari-Perez), Alpine 
region of Orizaba (Sumichrast°), La Parada (Boucard *), Omilteme and Amula in 
Guerrero (Mrs. H. H. Smith). 
P. leucogaster was described by Swainson from a specimen procured by Bullock at 
Temascaltepec in the highlands of Mexico!, Its range has now been ascertained to 
extend over a wide area, from the State of Sonora in the north-west to that of Guerrero 
and Oaxaca in the south. Specimens from different parts of this extensive tract of 
country do not vary to any appreciable extent; the northern birds are perhaps a shade 
paler, but that is all. 
The species is easily recognized amongst its allies by the size and white colour of the 
spots of its plumage, which have no fawn-colour or buff tint as is the case in P. affinis 
and P. compressus. 
2. Picolaptes affinis. 
Dendrocolaptes affinis, Lafr. Rev. Zool. 1839, p. 100°. 
Picolaptes affins, Lafr. Rev. Zool. 1850, p. 275°; Eyton, Contr. Orn. 1852, p. 22°; Scl. P.Z.S. 
1856, p. 289°; 1859, pp. 865°, 381°; 1864, p. 175"; Cat. Birds Brit. Mus. xv. p. 149°; 
Scl. & Salv. Ibis, 1860, p. 35°; Lawr. Ann. Lyc. N. Y. ix. p. 107 °°; Sumichrast, Mem. 
Bost. Soc. N. H. i. p. 555 (partim)“; La Nat. v. p. 248”; Salv. P. Z. S. 1870, p. 193”; 
Sanchez, Ann. Mus. Nac. Mex. i. p. 97 (partim?)™“; Ridgw. Pr. U. S. Nat. Mus. v. 
I 
p- 497°; Ferrari-Perez, Pr. U. S. Nat. Mus. ix. p. 156°. 
Thripobrotus affinis, Cab. & Heine, Mus. Hein. ii. p. 88”. 
BIOL. CENTR.-AMER., Aves, Vol. IL, September 1891. 24 
