487 



CORVINE. 



CROWS AND ALLIED SPECIES. 



The extensive and generally distributed family of the Cor- 

 vinse, composed of the genera Corvus, Pica, Garrulus, Nuci- 

 fraga, Fregilus, and a few others, has only nine representatives 

 among the species that occur in Britain, and of these one is 

 merely an occasional straggler. These birds agree in the fol- 

 lowing circumstances. They are all of considerable size, the 

 smallest, the Jay, being about as large as a common Pigeon, 

 while the Raven, which is the largest, equals the Domestic 

 Cock. Their body is ovate, compact, and moderately stout ; 

 their neck short ; their head large or of moderate size, oval and 

 rather flattened above ; their wings generally rather long, and 

 much rounded. 



The bill is in most cases about the length of the head, robust, 

 nearly straight, compressed towards the end ; the upper mandi- 

 ble with its outline more or less arched, its tip slightly de- 

 flected, the edges sharp with a slight notch or sinus close to the 

 end. The palate is flat or concave, and the upper mandible inter- 

 nally is marked with several longitudinal ridges. The internal 

 aperture of the nares is narrow and edged with small papillae. 

 The aperture of the glottis is defended behind by numerous 

 papillae, directed backv/ards. The tongue, PI. IX, Fig. 1, a, 

 is oblong, emarginate at the base, flat above, horny on both 

 sides and thin-edged towards the tip, which is slit, and more 

 or less lacerated on the margin. The fauces are of moderate 

 width, as is the oesophagus, b, c, d, which is of nearly uniform 

 diameter. The proventriculus, Fig. 4, d, bulbiform and en- 

 circled by a broad band of oblong or cylindrical glandules. 

 The stomach, Fig. 2, h, c, d, e^ is a gizzard of moderate power, 



