12 



CERTHIANtE. 



TREE-CREEPERS AND ALLIED SPECIES. 



The Certhianae are birds of small size, having the body short, 

 ovate, and compact ; the neck generally short ; the head rather 

 large and ovate ; the bill of moderate length or elongated, slender, 

 in some degree arched, with the notches obsolete, the tip acute. 

 Internally both mandibles are very narrow, concave, with a cen- 

 tral prominent line. The tongue is usually very slender, emar- 

 ginate and papillate at the base, channelled above, tapering, 

 with the point thin-edged, bristly, and rather obtuse. The 

 digestive organs differ little from those of the Sylvianse, the 

 oesophagus being of moderate width and nearly uniform 

 diameter ; the proventriculus oblong ; the stomach elliptical, 

 moderately muscular, the epithelium dense, with large longi- 

 tudinal rugae ; the intestine rather short and wide ; the coeca 

 very small, the cloaca globular. The trachea is also similar to 

 that of the Cantatores, having four pairs of distinct inferior 

 laryngeal muscles. Plate XIV, Fig. 1, 2, 



The nostrils are linear or oblong, exposed ; the eyes of mo- 

 derate size; the aperture of the ear large, and roundish. The 

 plumage soft and blended ; no bristle-feathers at the base of 

 the bill. VVings rather short, broad, concave, much rounded, 

 the first quill short ; tail short or of moderate length, rounded. 

 Anterior toes spreading little, coherent at the base, extremely 

 compressed, the outer longer than the inner, the hind toe very 

 long ; claws long, arched, extremely compressed, acute. 



To this group belong the genera Troglodytes, nearly allied to 

 the Sylvianae, Thyrothurus, Certhia, Tichodroma, and Upupa. 

 Only three species, Anorthura Troglodytes, Certhia familiaris, 

 and Upupa Epops, occur in Britain. 



