540 BULLETIN" 50, UNITED STATES NATIONAL MUSEUM. 



Medium-sized Troglodytidte (wino; 52-57 mm.) resembling I*li< m/o- 

 pedius^ but with tail graduated for much less than one-third its length; 

 ninth primary not distinctly, if at all, shorter than secondaries; nos- 

 tril broader than the narrow, corneous and excurrent operculum; 

 hallux (without claw) longer than outer toe (without claw), and with 

 concealed white spots on rump. 



Bill shorter than head, slightly but decidedly decurved, compressed: 

 exposed culmen much shorter than tarsus, about equal to middle toe 

 without claw, straight basally, then gradually but decidedly decurved, 

 or gradually curved from base; gonys decidedly shorter than distance 

 from nostril to tip of maxilla, straight or ver}' faintl}^ concave termi- 

 nally; maxillar}^ tomium faintlv concave, without trace of subterminal 

 notch; depth of bill at frontal anti{\3 greater than its width at same 

 point. Nostril ovate or guttate, overhung by a narrow excurrent 

 corneous operculum, its posterior end in contact with feathering of 

 latero-frontal antite. Rictal bristles obvious, two of them distinct. 

 Wing rather short, rounded; seventh, sixth, and tifth primaries long- 

 est, the fourth but little shorter and slightly longer than eighth, the 

 ninth about equal to secondaries or slightly shorter and decidedly less 

 than twice as long as tenth. Tail about four-lifths as long as wing, 

 rounded, the rectrices broadl}^ rounded at tip. Tarsus longer than 

 middle toe with claw, about two-tifths as long as wing and half as 

 long as tail, the acrotarsium distinctly scutellate, the planta tarsi 

 booted (sometimes, however, with three or more divisions on the 

 lower portion); lateral toes nearl}^ e([ual (the outer almost inappreci- 

 abh^ longer than the inner), both reaching (without claw) to just a 

 little beyond second (subterminal) joint of middle toe, their claws fall- 

 ing decidedl}" short of base of middle claw; hallux decidedly longer 

 than outer toe, its claw umch shorter than the digit; basal phalanx of 

 middle toe coherent to outer toe for al)out two-thirds its length, to 

 inner for more than half its length. 



Coloration. — A))Ove rust}' brown to grayish ])rown, the wings and tail 

 narrowly l)arred with dusky, the rump with concealed roundish spots 

 of white; a superciliary stripe and under parts liuffy or ochraceous, 

 the under tail-coverts barred with })lack. 



Range. — Eastern United States and northeastern Mexico. (Mono- 

 typic.) 



Nidification. — Nest in cavities, usually of stump, logs, or trees; 

 eggs white, speckled with reddish brown. 



KEY TO THE SCBSPECIES OK THRYOTHORrfS LUDOVICIANUS. 



«. AVing and tail longer (adult male averaging not less than 61.1, tail 52.5; adult 

 female averaging not less than wing 56.9, tail 47.4) ; upper parts brighter colored 

 (chestnut-brown or chestnut). 

 h. Smaller (adult male averaging, wing 61.1, tail 52.5, exposed culmen 16.2, tarsus 

 22; adult female, wing 56.9, tail 47, exposed culmen 15.7, tarsus 20.8); colora- 

 tion ]>aler (l)ack, etc., rusty brown or chesnut-lirown. under parts buffy wliitc 



