164 Mr. Svvu'mson on several new groups in Ornithology. 



Types. Le Curouge. Levaill. Ois. d'Af. pi. 107. f. 1. 

 Turdus Jtriceps. PI. Col. 147. 



It is only from the unusual shortness of the feet, indicative of 

 these birds feeding upon the wing, that I here associate them 

 among the aberrant forms of the sub-family Dicrurina. There 

 are many species, all of which appear excluded both from the 

 new world and Australia. 



In a natural series they will immediately follow the genus 

 Trichophorus. 



Sub-famili) Cninpepliagina ? 

 + PTILIOGONATUS. 



Rostrum breve, depressum, subtriangulare, culmine elevato, sub- 



arcuato ; tomiis rectis. paribus subnudis ; aperturd setts 



debilibus paucis instructd. 

 AlcB mediocres, rotu7idalcey remigibus 4'" et 5'" fere cequalibus, 



lo7igissi//tis. 

 Cauda subelotigatOy in medio subjurcata, reclricibus luteralibus 



rotundatis. 

 Pedes brevissimi) genibus pluniatis, ungiiibus parvis, acutis. 



Bill short, depressed, somewhat triangular; culmen elevated, 

 slightly curved ; commissure straight. Nostrils naked, the 

 aperture furnished with a few week bristles. Wings moderate, 

 rounded ; the fourth and fifth quill longest. Tail rather 

 lengthened, the sides rounded, the middle slightly forked. 

 Feet very short, knees feathered, claws small acute. 



Type. P.cinereus. Sw. Mex. Zool. 



p. cinereus ; mento rectricumque laternlium medio alb is ; caudce 

 tegmi?iibus infertoribus Jlavis ; alls cauddque nilide nigris. 

 Mas ? 



This is one of the most remarkable birds among those which 

 have been recently discovered in the interior of Mexico. It ex- 



