5 
PASSERES 
Geographical Distribution. Northern Hemisphere in general and greater part of 
Neotropical Region (Polioptila). 
Four genera with about fifty species and subspecies. 
Observations. Under the above heading I propose to unite the genera Lepflopoecile, 
Lophobasileus, Regulus and Polioptila, In external characters they closely agree with some of 
the genera generally included in the family Sy/viidae, while in habits they are more like the 
members of the Paridae, Until a thorough study of their anatomy be made, the proper syste- 
matic position of these birds cannot be considered as satisfactorily established, However, this 
question does not fall within the scope of Genera Avium, whose principal aim consists of 
giving a condensed synopsis of the various species of the different families of birds. 
KEY TO THE GENERA OF REGULIDA= 
1. Acrotaysium booted. Rectrvices rather broadened subleyminally, with pointed tip. 
General colour above olive green or greyish olive, crown in adults (except females 
of R. calendula) with a bright yellow, orange or ved patch. Tail slightly 
emarpinaie, fe so, Ge ew ee ee ee See GenUSEEGUInOSE 
— Acrotarsium distinctly scutellate. Rectrices broadly vounded at tip. General colour 
above never olive green or greyish olive, crown never with a bright coloured patch. . . . . «. « « « 2. 
2. Tail much rounded, the outermost vectrix being from 7 to ro mm, shorter than 
themedian No Crest’. 8s ke om 8) ss) cao 
— Tail nearly even, the outermost vectrix being scarcely 2 mm. shorter than the 
longest. With a long, full, white, occipital crest. . . . . . « « . 2. Genus LopHopasILEus. 
3. Nostrils wholly exposed, not covered by plumules. General colour above blue grey or 
Slatelovey) os Gh te, sy el ee ee eae Se? of ern as ee GDN Se OG LO RUNS 
— Nostrils posteriorly half concealed by the antrorse, bristly latero-frontal plumules. 
General colouy above olive grey or sandy grey, with crown veddish brown and 
yump pale Oluevand yinaccols =. = m =» = A «+ © 4) 0) 45) te GenusterrroporGime. 
I. GENUS LEPTOPOECILE SEvERTzow 
Leptopoecile Severtzow, Izv. Obshch. Moskov. Vol. 8, no. 2, p. 66 (1873) (Sp. un. : Leptopoecile sophiae 
Severtzow). 
Stoliczkana Hume, Stray Feathers, Vol. 2, p. 513 (1874) (Sp. un. : S. stolicskae Hume). 
Characters. Bill shorter than head, slender, acute; culmen slightly ridged, at base 
somewhat depressed and but faintly decurved terminally, no subterminal notch; gonys straight. 
Nostrils longitudinal, with a well-developed coriaceous operculum, posteriorly half concealed 
by the very fine, bristle-like latero-frontal plumules. Rictus with but few, soft bristles. Wing 
much rounded, the tip formed by the fourth, fifth and sixth primaries, which are nearly equal 
in length; first primary about half as long as second, Tail longer than wing, distinctly rounded, 
the outermost rectrix being from 7 to Io mm, shorter than the longest. Tarsus relatively 
strong, in front distinctly scutellate, more than twice as long as hind toe without claw. 
Plumage soft and lax, 
