230 NORTH AMERICAN BIRDS. 



Family TROGLODYTID^. — The Weens. 



Ch.\b. Rictal bristle.s wanting , the loiiil Il-uiIilts with bri.stly points ; the frontal 

 featliers generally not reaching to nostrils. Nostrils varied, exposed or not covered by 

 leathers, and generally overhung by a scale-like memlirane. Bill usually without notch 

 (except in some Middle American genera). Wings much rounded, about equal to tail, 

 which is graduated. Primaries ten, the lirst generally about half the second. Basal joint 

 of nnddle toe usually united to half the basal joint of inner, and the whole ol' that of the 

 outer, or more. Lateral toes about equal, or the outer a little the longer. Tarsi scutellate. 



Tlie iiiipossilnlity of defining any large grouj) of animals, so as to separate 

 it striugeutly and abruptly from all others, is well understood among natu- 

 ralists ; and the Troijlodijtidm form no exception to the rule. Some bear so 

 close a resemblance to the Mocking Thrushes as to have been combined with 

 them ; while others again exhibit a close approximation to other subfamilies. 

 The general affinities of the family, however, appear to be to the Turdidcc, 

 and one of the best characters for se{)arating the two families ajipears to exist 

 in the structure of the feet. 



In the Ttirdidw the basal joint of tlie outer lateral toe is united to the 

 middle toe, sometimes only a part of it ; and the inner toe is cleft almost to 

 its veiy base, so as to be opposalilc to Die hind toe, separate from the others. 

 In the Tn>;/lodi/tida-,<)n the contrary, the inner toe is united by half its basal 

 joint to tlie middle toe, sometimes by the whole of tliis joint ; and the second 

 joint of the outer toe enters wholly or partially inln this unicin, instead of 

 the basal joint only. In addition to this character, the open, exposed nos- 

 trils, the usually lengthened bill, the generally equal lateral toes, the short 

 rounded wings, the graduated tail, etc., furnish points of distinction. 



Genera. 



A. Lateral toes very unequal. 



n. Culmen depressed basally, the interval lietween the nostrils wider than 

 the much compressed anterior half of the bill. Plate on tlu^ posterior half 

 of the tarsus continuous. Catberpes. 



b. Culmen compressed basally, the interval between the nostrils narrower 

 tlian the rather depressed anterior half of the bill Plate on the posterior 

 half of the tansus broken into smaller scales. Salpiuctes. 



B. Lateral toes equal. 



c. Length about 8 inches. Campylorhynchus. 



d. Length less than 6 inches. 



Bill abruptly decurved or hooked at the tip. Outstretched feet not 



reaching near to end of tail. Thryothorus. 



Tail longer than the wing, the featliers black, variegated terminally 



with whitish ' Subgenus Thr ji oman er.. 



Tail shorter than tlie wing, the feathers rusty, not variegated with 



whitish Subgenus Thryothorus. 



Bill only gently curved at the tip. Outj^tretched li;et reaching nearly to 



or bevond the end of the tail. 



