338 



XORTH AMERICAN BIRDS. 



blotches, and points of nMldish-brown. These markings vary greatly in size, 

 number, and distribution. Tiiey are usually chiefly about the larger end. 

 In .shape they are u.sually less elongated than those of the liarn Swallow, and 

 their markings are larger. This is not, however, invariable, and the two 

 kinds are not always distinguishable. In length they vary from .875 of an 

 inch to .75, and their average breadth is .60. 



(J EX us HIRUNDO, Linn. 

 Ilirundo, LlSN. Sy.st. Xat. 1, Idth .mI. 17.58, 191. (Type, 77. rmlim, I, inn.) 



Under the generic head of Hirurulo I propose to combine several groups 



of American Swallows 

 agreeing in moderate, 

 dei)ressed bill, with 

 straight commissure, 

 and lateral nostrils 

 overhung by mem- 

 brane; the tarsi feath- 

 ered only at the upper 

 end, or else entirely 

 bare; the lateral claws 

 moderate, not extend- 

 ing lieyond the base 

 of the median ; the edge of the outer primary ^vithout hooks ; the tail varia- 

 ble in cliaracter, from a very deep fork to a slight emargination only. 



Subgenera. 



Tarsi sli<:litly foathero.l m, inner faro at upp'T end ; equal ii, length to niidcUe toe 

 without elaw. ,„ , 



Tail verv deeply lork(>il .....■• 



Tail .sh.Lihtly forked or einarirmate ..•■•■• ' ■> 



Tar.=i entirelv naked; lenplhened equid to middli" toe and half its elaw. 

 Tail cousidei-ablv lorked ...••■• 



Uininilo horrfoTinn. 



SuHdKxrs HIRUNDO, bixN- 



Okv. CnAR. Xostrils lateral. Tarsi .short, not exeeodinfr niiddl.' toe without its elaw ; 

 the upper joint .'oveivd with feathers, whii'h extend a short distance along the iunor faeo 

 of tarsus. ' Tail very deepiv forked; the lateral feather niueh attenuated, twice M lon/r a.s 

 the middle. Hasai joint i.f mid.lle toe free for terminal fourth on outside, for halt on 

 inside. Nest partly of muil. and lined with feathers; eir^'s spoiled. 



In type, and in Ameriean .speei.^s. the lorohead and thnuil rufons; a I. lack pectoral collar ; 

 tail-feathers with lar^o li.irht spots on inner wehs. 



1 ('. ,;i<i,inn-ii-idls, liiiVANT ; I'.Mlin, Hev. :'.o:! (lialiamas). 



