20 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



1. Bill much longer than head, subulate, slightly decurved termi- 

 nally, or else slender-conoid, with tip acute; if the latter and not 

 decurved terminally, the tail decidedly longer than distance 



from bend of wing to tip of secondaries ' Coerebidse, part. 



a. Bill always shorter than head, subulate, slender-conoid, or rather 

 stout but compressed; never decurved; if acute at tip the tail 

 not longer than distance from bend of wing to tip of secondaries; 

 if rather stout the culmen decidedly but gradually curved. 



Hniotiltidae.^ 

 ff. Tertials conspicuously elongated, reaching nearly if not quite to tips of 



longest primaries, the bill slender, almost subulate Motacillidae. 



ee. Width of bill at rictus equal to or greater than length of culmen. 



ProcniatidsB (extralimital).' 



(id. Longest primaries more than twice as long as secondaries . . .Hiruudinidae. 



cc. Tip of maxilla abruptly uncinate, the bill narrow and straight; maxillary 



tomium not toothed subterminally; mandible not falcate; angle of chin 



anterior to nostrils Vireonidae, part. 



' According to the above diagnosis Coniroslrum sitticolor would not be one of the 

 Coerebidse, but referable to the Mniotiltidse, and I am by no means sure that 

 such is not its proper position, together with the other species of the same genus. 

 At any rate, I fail to find any external differences whatever, of more than generic 

 value, between these birds and the supposedly Mniotiltine genus Oreothlypis. Possi- 

 bly the latter should be referred to the Crerebidse, but if so it is difficult to see why 

 Compsothlypis should not go with it. I would also eliminate from the Coerebidas part 

 of the genus Dacnis, transferring D. pulcherrima to the Tanagridse (as a new genus, 

 Iridophanes) and the Atelodacnis section to the Mniotiltidse, near Compsothlypis, Hel- 

 minikophila, etc. Whether such disposition of these forms is really the proper one 

 can only be determined by study of their anatomy; but unless this course be adopted 

 it is, apparently, impossible to intelligibly characterize the Ccerebidse and Mniotil- 

 tidfe as distinct groups, which undoubtedly they are if properly circumscribed. 



^ Certain genera of Coerebidse are distinguished from all Mniotiltine genera whose 

 osteology has been studied by the following characters: 



Coerebidse. — Interpalatine process small or abortive; transpalatine process slender, 

 spine-like; palatines produced posteriorly and overhanging anterior ends of ptery- 

 goids; tongue slender, with terminal portion extensively bifid or trifid, and brushy 

 or laciniate. 



Mniotiltidse. — Interpalatine process well developed; transpalatine process short and 

 bluntly angular; palatines not produced posteriorly over pterygoids; tongue shorter, 

 broader, with terminal portion but slightly cleft or brushy. 



The above distinctions hold good between Cosrcia, Cyanerpes, and Glossiplila (CcBre- 

 bidfe) on the one hand and Dendroica, " Perissoglossa ," Geothlypis, Compsothlypis, and 

 Certhidea (Mniotiltidse) on the other. (See Lucas, Proc. U. S. Nat. Mus., xvii, 1894, 

 299-310.) The supposedly Coerebine genera Chlorophanes, Oreoinanes, Hemidacnis, 

 Dacni-i, Atelodacnis, and Conirostrum have not been examined anatomically, and until 

 these have been investigated, together with the supposedly JIniotiltine genus 

 Oreothlypis and Tanagrine genera Iridophanes (type, Dacnis pulcherrima Sclater), 

 Hemithraupis, and Chlorochrysa-, the line separating the Coerebidse from the Mniotil- 

 tidse on the one side and from the Tanagridaj on the other can not be considered as 

 established. 



'Lucas, The Auk, xii, April, 189.i, 186; Proc. U. S. Xat. Mus., xviii, 1895, 505-507; 

 RiDGWAY, Proc. U. S. Nat. Mus., xviii, 1895, 449, 450. This family is represented by 

 a single nlonotypic genus, Procnias Illiger (Prodromus Orn., 1811, 228; type, ^impelis 

 tersa Linnseus), which ranges from Colombia over the Amazonian and Brazilian 

 provinces of South America. 



