476 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



second joint of the outer toe enters wholly or partially into this union, 

 instead of the basal joint only." 



Notwithstanding- the ver}^ g-reat range of variation in details of 

 external structure (which, however, affect chiefly the character of the 

 nasal aperture, relative length of wing and tail and of lateral toes), the 

 group is a very natural one and does not contain a single genus whose 

 position in the group is in the least degree questionable. Much has 

 been made of the alleged abnormal character of the planta tarsi in the 

 genera Salpinctes^ Catherpes^ and "" Campylorhy7iGhus'''' {Ileleodytes)^ 

 in which the postero-lateral plates of the tarsal covering (composing 

 the planta tarsi), especiallj^ the outer one, are alleged to be '"broken 

 up into a series of conspicuous scutella,"" these plates in "normal" 

 Troglodytidas being continuous or undivided. After most careful 

 examination of this character, hbwever, I iind that the alleged dis- 

 tinction between the above-named genera and other members of the 

 group does not, as a matter of fact, exist, the division of the outer 

 (sometimes also the inner) plate of the planta tarsi appearing occa- 

 sionally in many other genera besides those named, while in the 

 latter it is of decidedl}^ exceptional occurrence except in Salplnctes^ 

 in which the division is sometimes reduced to less than the lower half 

 of the plates in question. Salpinctes and Catherpes^ together with 

 Hyhyrchllns^ are, without doubt, "aberrant" members of the group in 

 the extreme abbreviation of the lateral toes, especially the inner, but 

 Telmatodytes and Oistothorxis are equally if not more so in the cohesion 

 of the hallux to the inner toe and in having the inner toe longer than 

 the outer (instead of the reverse); but Ileleodytes is so clearl}" a t3'pical 

 Wren that it may be considered one of the most generalized mem- 

 bers of the family and therefore offering more difficulties in the way- 

 of diagnosis than almost any other. 



The Wrens are birds of variable appearance and habits, though 

 mostly agreeing in a dull brownish, more or less barred, coloration, 

 and semiterrestrial habits. Many are fine songsters, members of the 

 genera Ileleodytes^ Thryophihis^ Thryothorus^ Microcercidus^ and Leu- 

 colepis^ being, in fact, songsters of the first order. 



The family is poorh^ represented in the Eastern Hemisphere, where 

 onl}^ fifteen species, referable to five genera, are known, these restricted 

 to Europe and the temperate parts of Asia, chiefly the latter. In 

 America, however, it is numerously developed, especialh' within the 

 Tropics, nearly one hundred and fift}^ species, belonging to fourteen 

 genera, being known to occur there. 



KEY TO THE GENERA OF TROGLODYTID^. 



a. Tail at least half as long as wing, much longer than tarsus. 



h. Lateral toes longer, the inner reaching (without claw) to or beyond penultimate 

 joint of middle toe, the outer reaching decidedly beyond. 



« See Coues, Bull. Nutt. Orn. Club, i, 1876, 50, 51. 



