﻿BIRDS OF THE TRES MARIAS ISLANDS. 



47 



Measurements of lache lawrencei and I. latirostris. 



'Name. 



laclie lawrencei 

 lache lawrencei 

 laclie latirostris 

 laclie latirostris 



Locality. 



.do 



Southern table-lands, Mexico . - . 

 do 



Sex. 



jSTum- 

 her of 

 speci- 

 mens. 



Wing. 



Tail. 



Ctil- 

 men. 



ad. cT 



3 



52.3 



32.6 



18.8 



ad. ? 



i 



51.2 



29.2 



20.2 



ad. 



5 



54.2 



33 



21.9 



ad. ? 



1 



52 



33 



23 



Platypsaris aglaiae insvilaris (Eidg.) Graysou's Becard. 



Hadrostomus aglaia' var. affinis Grayson, Proc. Boston Soc. Nat. Hist., XIY, p. 279, 



1871 ; Law r., Mem. Boston Soc. Nat. Hist., II, p. 289, 1874. 

 Platypsaris iusiilaris Ridgway, Man. N. Am. Birds, p. 325, 1887. 



The rose- throated becarcl was iiot common and only three specimens 

 were taken, all on Maria Madre. They were found in the hoavier 

 forest ou the slopes well back from the coast, and nothing unusual was 

 noted in regard to their habits. They probably occur on Maria Mag- 

 dalena and perhaps on Maria Cleofa. A considerable series of speci- 

 mens from various parts of Mexico shows that a single species of rose- 

 breasted becard ranges over a large part of Mexico and has developed 

 four geographical subspecies. The ranges of these four forms may be 

 defined as follows : 



Platypsaris aglam (Lafr.). Eastern Mexico from northern Tamau- 

 lipas south along basal slopes of the Cordillera of Vera Cruz and 

 Tabasco to arid parts of Yucatan. (Type from vicinity of Jalapa, Vera 

 Cruz.) 



Platypsaris aglaiw sumichrasti kelson. Humid lowlands of Yera 

 Cruz, and thence southward in similar country nearly or quite to Guate- 

 mala. (Type from Otatitlan, Yera Cruz.) 



Platypsaris aglaiw albiventris (Lawr.). West coast of Mexico from 

 the Isthmus of Tehauntepec to southern Arizona, raugiu^' along river 

 valleys into the ioterior of western Mexico. (Type Irom Plains of 

 Colima ) 



Platypsaris aglaice insularis (Ridg.). Tres Marias Islands. (Type 

 from Maria Madre Island.) 



Typical specimens of insularis nre much darker than typical examples 

 of albiventris. Specimens from the coast lowlands about San Bias are 

 intermediate in color. The island birds, however, may usually be dis- 

 tinguished by their smaller bills. Back from the coast of Tepic, 

 especially in the arid river canyons at Bolanos and near Guadalajara, 

 only typical specimens of albiventris were found. On the eastern side 

 of Mexico these two forms are paralleled by the pale bird of the foot 

 hills and adjacent interior {aglaiw) and the darker one of the coast 

 lowlands {snmichrasti). The color of extreme specimens of albiventris 

 is very different from that of aglaiw and instilaris, but among the series 

 from western Mexico, where albiventris has its home, are various inter- 

 mediate stages, some specimens approaching very closely to both the 



