96 TROGLODYTID 2. 
other, 7. spilurus, in California. The differences 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?®. 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 
bewicki, 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 
bairdi. | 
Of T. bairdi 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 7. dewicki from Brazos in Texas. 
This, with the good series of 7. spilwrus 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 7. 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 difficult 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 isyalmost 
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 difficult questions 
* Anted, p. 78. 
