160 APPENDIX. 



the bill on each side (see fig. 1, p. 159). The bill is in reality long and strong, and the gape very 

 wide ; but the basal half is entirely concealed from view by this extraordinary development of 

 the loral plumes. It is, I suppose, for the purpose of getting the nostrils out of the way of these 

 that the openings of them are carried so far forward. They are placed laterally, rather nearer 

 the apex of the beak than the front (where the feathering commences), and consist of a narrow 

 diagonal slit, just as in the genus Eurystomus. But in Eurystomus the apertures lie, as is the 

 case in the majority of birds, at the base of the beak close to the frontal plumes. On examining 

 the skeleton of Leptosoma we see at once that this remarkable formation has been effected by the 

 elongation of the basal portion of the beak, and that the lateral coverings of the nasal passages 

 (alas nasi), which in most birds are entirely membranous, have in this form become completely 

 ossified, so as to add very materially to the strength of the upper mandible (see fig. 2, p. 159). 



A very similar formation occurs in Eurystomus, but is not carried to the same extent, the 

 covering of the nasal passages remaining membranous in this form. 



The wings of Leptosoma are of moderate length, reaching to about half the length of the tail 

 from its base. The primaries are ten in number, the third, fourth, and fifth being nearly equal 

 and longest, the second half an inch shorter, and the first more than an inch shorter again, being 

 about equal to the eighth. The first six are narrowed towards the apex ; the remaining four are 

 broad-tipped like the secondaries. The secondaries are twelve in number. 



The tail consists of twelve rectrices of nearly equal length, and squared at the apices. 



The feathering of Leptosoma presents some remarkable characters. The body-feathers have 

 a long downy aftershaft, longer than half the length of the feather itself (see figs. 3 and 4). In 



FIG. 3. 



FIG. 4. 



Feathers of Leptosoma. 



Eurystomus there is a similar auxiliary plume, but not quite so highly developed. In the Cuculidce, 

 I believe, the aftershaft is always deficient. 1 The upper ptilosis also appears nearly similar to that 

 assigned by Nitzsch to Coracias and Eurystomus. The spinal tract bifurcates between the 



1 Cf. antek, p. 90 et seq. 



