TKOGLOnVT [ I ».F. — THE WREXS. 



141 



Gi:m. THRYOTHORUS, Vikiix. 



ThryoOwnis, Vieillot, Analyse, 1816, 45. (Type, Troglodytes armidinaccun, "Troglodyte 

 dcs lloscmix," ViKn.L. Ois. Am. Sept. II, 1807, 55 = Sylvia ludoviciana, Lath.) 



Gev. Chak. Bill compressed, rather slender; height about one fourth the length above. 

 Culmen and commissure gently cm-ved throughout; gonys straight; tip very obsoletely 

 notched. Nostrils in the lower edge of anterior 

 extremity of the nasal groove, narrowly elliptical, 

 overhung l:)y a stiff scale-like roof of the thickened 

 membrane of the upper part of the nasal groove, the 

 crescentic edge rounded. The septum of nostrils 

 imperforate; the posterior part of the nasal cavity 

 with a short septum projecting into it parallel with 

 the central, not pevpenilicular as in Microcerculiis. 

 Wings and tail about equal, the latter moderately 

 rounded ; the first primary more than half the 

 second, about lialf the longest. Tarsi rather sliort, 

 scarcely exceeding middU; toe Anterior scutelliu Thri/oihoms imlaviricianus. 



distinct, rest of each side of tarsi in a continuous plate. Lateral toes equal. 



The diagnoses of tlie North x^merieaii sitecies are us follows : — 



Species and Varieties. 



CoM.MON Characters. Head aliove, and back, of nuieh the same color. Cris- 

 sum barred transversely ; rest of under parts plain. L'pper tail-coverts and ex- 

 posed surface of wings barred. Iris hazel. Nest in liules or with an arched 

 covering. Eggs reddish-white, spotted with red and purple. 



ft. Tliryothoriis. 

 T. ludovicianus. Tail-feathers redilish-lHown, barred with black. Greater 

 wing-coverts si)Otted witli whitish. 



Beneath yellow-whitisli, washed occasionally with rusty. Sides plain. 

 Bill from nostril, .45. Length, 6.00. Iliih. Eastern Province United 

 States .......... var. ludovicianus. 



Beneath rufous; lighter on throat and along median line. Sides 

 obsoletely barred with dusky. Bill from nostril, fiCu Length, 5.25. 

 Hrib. Lower Rio Grande. var. berla u Jieri. 



h. TehniitmJyfes. 

 T. be'wickii. Tail-feathers, except central, black ; the exposed surface and 

 tips only varied with white. Length, 5.50. 



Above dark rufous-brown; beneath plumbeous-wliite ; flanks tingiMl 

 with brown. Rump and exposed secondaries distinctly banded. Cjuills 

 and middle tail-feathers brownish-black. Length from nostril, .39; 

 along gape, .70. Hah. Eastern Province United States. var. betuickii . 



Above ashy-brown ; beneath, including flanks, clear white ; rump 

 ashy, and, like secondaries, very obsoletely barred. Quills and middle 

 tail-feathers grayish-brown. Hah. Southern border of United States, 



into Mexico var. leucogaster. 



Colors intermediate between the two last. Bill longer, from nostril, 

 .50, from gape, .81. Ilah. Pacific Province . . . . \m: spilurns. 



