PHRENOTRIX TEMIA. 
explain the considerations by which I have been guided, to represent in the Plate of 
Illustrations, a comparative view of the bill of Phrenotrix in letter N. a. & 6. ; of 
Corvus Pica in letter O. a. & k ; and of Corvus senegalensis in letter P. Phrenotrix 
is distinguished by an elevated, regular, and smooth bill, gradually tapering to a 
rounded keel, equally arched from the base to the point, and by a thick velvet-like 
border wliich surrounds the bill and orbits : the nostrils also have a very peculiar 
form and disposition. The Senegal crow has a similar deposition of the nostrils ; but 
the bill, although smooth, regular, and arched, is more lengthened, and the culmen 
comparatively sharp. No traces of the velvet-like border exist, but the base of the 
bill is entirely without that peculiar character which is observed in Corvus Pica. 
Here it is covered by numerous, very stiff, decumbent, jagged bristles, pointing 
directly forward far beyond the nostrils; the latter are perfectly circular in a gradually 
narrowed depression. The form of the bill is lengthened, the arch less prominent, 
and it has a distinct terminal notch, which in Phrenotrix and in Corvus senegalensis 
is very obsolete. 
