95 TEOGLODTTID^. 



other, T. spilurus, in California. The diiFerences between these three forms were first 

 set forth by Prof. Baird in his ' Review of American Birds '^ ; and his views have been 

 confirmed by subsequent writers ^ 5, These forms are stated to be strongly marked 

 geographical varieties separable by quite constant characters ^, necessitating, in our 

 opinion, the use of a specific name for each, the fact of this constancy of character 

 rather than the amount of the difference between them requiring this recognition. 



In differentiating these races, Prof. Baird thought that he recognized in the Mexican 

 bird the Troglodytes leucogastra of Gould, and hence properly called it Thryothorus 

 hewicM, var. leucogaster. But Mr. Gould's name has since been found to apply to a 

 very different species, which now stands as Uropsila leucogastra*. This being the case, 

 it is obviously undesirable to retain the name leucogaster for the present bird as well 

 as for the Uropsila ; we therefore suggest that the former should stand as Thryothorus 

 hairdi. 



Of T. hairdi in Mexico little is recorded beyond its occurrence at several places 

 as far south as the State of Oaxaca ^ and the Isthmus of Tehuantepec ^ ; but good 

 accounts of it are given by Mr. Sennett ^ and Dr. Merrill ^, who observed it on the Rio 

 Grande, and also by Mr. Ridgway^ and Dr. Coues^. All these observers bear 

 testimony to the excellence of its song and the great variety of its notes. Dr. Merrill 

 describes its nest as placed in various situations, such as an old Woodpecker's hole, 

 between joints of a prickly pear, or amongst twigs of dense thorny bushes. The eggs 

 are described as varying considerably, some having very fine inconspicuous markings, 

 others heavy marks of reddish and lilac. Our thanks are due to Mr. Ridgway for 

 lending us for comparison a specimen of the true T. bewicM from Brazos in Texas. 

 This, with the good series of T. spilurus in the Museum of the University of Cam- 

 bridge, formerly in Hepburn's collection, and specimens of the Mexican bird in our 

 own and Mr. Sclater's possession, have enabled us to compare the three races of this 

 Wren together, and to confirm, as far as our materials go, the observations of American 

 writers. 



TROGLODYTES. 



Troglodytes, Vieillot, Ois. Am. Sept. ii. p. 52 (1807). (Type T. aedon, Vieill.) 



No well-marked characters distinguish Troglodytes from Thryothorus, though the 

 small size, more slender straighter bill, and shorter tail of the more typical members 

 of Troglodytes render them not diflacult of recognition when compared with any of the 

 sections of Thryothorus, into which the species of that genus have been grouped. Still 

 such birds as the West-Indian Thryothorus martinicanus and its allies are so inter- 

 mediate in their characters that the passage from one to the other genus is almost 

 complete. 



The classification of the races of Troglodytes allied to T. aedon, owing to the great 

 amount of variability observable amongst them, offers one of those difiicult questions 



* Anted, p. 78. 



