ANATOMY OF THE SHOE-BILL. 649 



that "as the middle claw is not pectinated, Balceniceps cannot 

 be referred to the Herons," adding " Piofessor Reinhardt would 

 associate Balceniceps particularly with Scopus," but omitting to 

 mention that in the same paper Reinhardt stated that the claw 

 was pectinated also in Scojnis. Mr. A. H. Evans (8, p. 87) 

 divides the Sub-order Ardese into the Families Ardeidae (in 

 which he places Balcenicejys) and Scopidfe, and states that in the 

 Sub-order the " claw of the middle digit is toothed on the inner 

 side, save in Balceniceps." It is surprising that as Gadow, 

 Beddard, and Evans all seem to have thought the matter worth 

 comment, they should have omitted to notice Giebel's (21, p. 351) 

 very definite description. Giebel stated that in the two examples 

 of Balceniceps he had examined the pectination was clear and 

 sharp, the actual teeth being not so small, numerous and deeply 

 incised as in Canc^^oma and Nycticorax, but larger, separated by 

 wider intervals, and, beginning at the point, reaching nearly the 

 middle of the nail. He described them as closely corresponding 

 with those of b'cojnis, adding that the latter had not received full 

 attention from systematists. 



I hope that the drawings reproduced in the figure (text-fig. 

 120), which were made by Mr. Berridge from the actual specimens, 

 will explain the matter. In a large number of birds belonging 

 to different groups, the claw of the third toe of each foot is not 

 symmetrical about the middle line ; the ulnar or abaxial edge is 

 i-elatively straight, and the radial edge, that nearest the body, is 

 curved out into a sharp-edged scoop. The foot of the White Ibis 

 (fig. 120, 1) shows this condition well. In Balceniceps (fig. 120, 2), 

 owing to the lateral compression of the claws, the scooped edge is 

 not quite so conspicuous in a dorsal or lateral view, but it exists. 

 Moreover, as Giebel described, this sharp edge is marked by a few 

 serrations between each of which there is rather a wide space, 

 but which are so conspicuous on the claw that they can be felt 

 not only along the edge but as slightly ribbing the surface. In 

 Scopus (fig. 120, 3) the condition of the claw is almost exactly 

 similar to that in Balceniceps. In the examjDle I examined and 

 from which the drawing was made the serrations were cut a 

 little deeper than in Balceniceps, but according to Giebel, in the 

 specimens of Balce?iiceps he examined, the sensations were deeper. 

 The exact amount of serration is no doubt subject to individual 

 variation. In the corresponding claw of the left foot of the 

 Timbre I examined, each tooth was much narrower and moi-e 

 pointed, resembling the Balceniceps condition more closely. In 

 the Little Bittern (fig. 120, 4) and in the Goatsucker (fig. 120, 5), 

 the teeth are much more numerous, regular, smaller and moi'e 

 closely set together, and when the comb is highly developed, 

 it may stand out conspicuously from the edge of the claw, 

 sometimes by not being developed along the whole edge, and 

 sometimes because the thin edges of the teeth give the comb a 

 yellow semi-transparent coloration, readily visible against the 

 duller and more opaque unbroken part. Almost every gradation 



