XXVll 



VI. Structure of the Puff-Urds. 



I am again indebted to Mr. Forbes for the whole of the subjoined notes upon the stracture 

 of the Bucconidse. 



a. External Features and Pterylosis*. 



The nostrils are much as in the Galbulidae, with a large operculum, and forwardly directed 

 setse, continuous behind with the rictal series, but shorter than those in the allied family. 

 There are apparently eyelashes, which, however, have more the form of feathers than they have 

 in the Galbulidse. 



The feet are stronger than those of the Galbulidae, but essentially similar in construction, 

 having both the first and fourth digits permanently reversed. The anterior semicircumference 

 of the tarsi is covered with transverse scutellse ; behind they have two series of quadrangular 

 scales in contact with each other along the median line. The second digit is united with the 

 third, but less intimately than in the Galbulidae, the union not extending beyond the first 

 phalanx of the digits. 



The oil-gland is nudef. There are twelve rectrices, , the outer pair of about the same 

 length as their fellows. The number of remiges seems to be twenty-two or twenty-three, of 

 which ten are always primaries. As in the Galbulidae, the " first " of these is much shorter than 

 the others. The contour-feathers have no aftershaft. 



Nitzsch has described J the pterylosis of JBucco collaris, B. chacuru, and B. tamatia, as well 

 as that oi Malacoptila fusca, and given figures in the case of the last two species. The tracts are 

 all narrow, but the feathers on them strong and closely inserted. It is unnecessary to describe 

 the arrangement of the tracts in detail, as it almost precisely corresponds with that of the 

 Galbulidae already described. The main differences between the two are : — 



1. The absence of an aftershaft. 



2. The absence of an internally directed " gular " branch from the pectoral tract. 



3. The much clearer break between the anterior and posterior portions of the dorsal tract, 

 there being a considerable space between the two, with no connecting series of feathers. 



4. The greater length of the united part (or " handle ") of the posterior fork. 



5. The somewhat wider nature of the tracts. 



b. Visceral Anatomy. 



Of the visceral anatomy of the Bucconidse all we at present know is that they have a 

 capacious oesophagus, a fairly thick-walled muscular gizzard, no gall-bladder, and a short 

 intestine, provided with the long, globose caeca characteristic of all the allied groups of birds. 



* I have unfortunately as yet only been able to examine skins of this group. The following notes are based chiefly 

 on an examination of Bucco maculatus ; but I have comjjared imperfect skius of Monaclui panamensis, M.fiavifostris, and 

 Chelidoptera tenebrosa. — W. A. F. 



t I*ritzsch (infra cit. p. 95) describes it as having " a few fine hairs at the apex " in Malacoptila fusca. These I have 

 been unable to detect in any species examined by me. 



J Pterylography, Kay Soc. ed. pp. 94, 95, pi. v. figs. 9, 10, 11. 



d2 



