120 REVIEW OF AMERICAN BIRDS. [PART I. 
flanks, anal region, and crissum somewhat like the back, but paler ; 
the sides of the breast tinged with plumbeous. Length, 3.50; 
wing, 2.05; tail, 1.35. 
Smith- Collec- Sex , When ; 
sonian| tor’s | and Locality. Galléctod Received from 
Collected by 
No. No. | Age. 
22,386 |40,727 | ¢ | Mexico (Oaxaca?) sa Verreaux. | eb to 
(22,386.) Type. 
THRYOTHORUS, Vier. 
Thryothorus, Virintor, Analyse, 1816, 45. (Type Troglodytes arundi- 
naceus, “ Troglodyte des Roseaux,” ViEiuu. Ois. Am. Sept. II, 1807, 
55 = Sylvia ludoviciana, Lat.) 
Bill compressed, rather slender ; height about one-fourth the length above. 
Culmen and commissure gently curved throughout ; gonys straight; tip very 
obsoletely notched. Nostrils in the lower edge of anterior extremity of the 
nasal groove, narrowly elliptical, overhung by 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 perpendicular as in Microcerculus. Wings and tail about eyual, the latter 
moderately rounded ; the first primary more than half the second, about half 
the longest. Tarsi rather short, scarcely exceeding middle toe. Anterior 
scutelle distinct, rest of each side of tarsi in a continuous plate. Lateral 
toes equal. 
The type of the genus, as established by Vieillot, is his Troglo- 
dytes arundinaceus, by G. R. Gray and others referred to the Cisto- 
thorus palustris, but while the account of the nidification and general 
habit applies best to the latter, the description and figure unquestion- 
ably relate to 7. ludovicianus. (See also Baird, Birds N. Am. 
1858, 359.) 
As remarked elsewhere, the Wrens formerly included in the genus 
Thryothorus are found to embrace several distinct groups character- 
ized by the form of the nostrils, and to some extent by the shape of the 
bill and the degree to which this is notched at the tip. As restricted, 
the species of Thryothorus, characterized by the linear nostrils 
moderately overhung by a thickene@ scale, all belong to North 
America, and constitute two sections: one with 7. ludovicianus as 
type; the other (Thryomanes, Sclater) with slenderer, longer bill, 
and the tail longer than the wings, its feathers broader, best repre- 
sented by bewickiz. 'The other divisions—Pheugopedius and Thryo- 
philus—are peculiar to Middle and South America. 
