446 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



oval or subacuminate, with rather broad superior opereulum or mem- 

 brane. Rictal bristles obsolete. Wing moderate or rather long, with 

 three to four outermost primaries abruptly longest (ninth usually- 

 equal to or longer than sixth ^) ; wing-tip usually shorter than tarsus.^ 

 Tail equal to or longer than distance from bend of wing to tips of 

 secondaries (except in H. peregrina), even, slightly emarginate, or 

 double-rounded, the rectrices rather narrow. Tarsus much longer than 

 commissure, nearly-one third as long as wing (except in H. peregrina), 

 its scutella indistinct; middle toe, with claw, decidedly shorter than 

 tarsus; basal phalanx of middle toe united for more than half, some- 

 times most of, its length to outer toe, for about the basal half, or 

 slightly more, to inner toe. 



Coloration. — Very variable, but never with the throat orange nor 

 back black; if with a white superciliary stripe (extending above auric- 

 ulars) the forehead yellow and a yellow patch on middle and greater 

 wing-coverts. 



Nidification. — Terrestrial, or (in H. lucice) the nest placed in holes 

 or behind bark of stumps or tree trunks. 



Range. — North America in general, including highlands of Mexico; 

 Central America and northern South America and Cuba in winter. 

 (Ten species.) 



There is considerable variation in details of external structure in 

 this genus. H. peregrina stands alone in having the wing-tip much 

 longer than the tarsus, the tail shorter than distance from bend of 

 wing to tip of secondaries and decidedly emarginate, and is besides the 

 only species without yellow on under parts and at the same time with- 

 out chestnut or tawny-ochraceous on crown. H. rvhricapiUa is unique 

 in the short ninth primary, which is shorter than the sixth instead of 

 equal to it or longer. H. iachnani has the bill decidedly more slender 

 than other species, and with a perceptible downward trend at the tip. 

 It also has the frontal feathering more deeply cleft by the sharply ridged 

 culmen, the latero-frontal antise forming an acute angle in the poste- 

 I'ior portion of the more narrow nostrils. H. chrysoptera, H. pinus, 

 and If. lucim have the anterior toes more united basally, the basal 

 phalanx of the middle toe being joined for most of its length to the 

 outer toe and for more than half its length to the middle toe. 



KEY TO THE SPECIES AND SUBSPECIES OP HELMINTHOPHILA.' 



a. Wings bicolored (tips of middle and greater coverts more or less extensively yellow 

 or white). 

 b. Throat and auricular region black (adult males) or gray or olive-green (adult 

 females). 



' Shorter than sixth only in H. rubricapilla. 



* Equal to tarsus in H. pinus and H chrysoptera, longer in H. peregrina. 

 ^ H. dncinnatiensis (Langdon) is not introduced into the "key" for the reason 

 that it is obviously a hybrid between H. pinus and Oporomis formosa. (See Bidg- 



