xu 



II. Structure of the Jacamars, 

 Having said thus much as to the place in the Systema Avium of these two families, I will 

 proceed to the following remarks upon various portions of their structure, which, as already 

 mentioned in the Preface, Mr. W. A. Forbes has most kindly drawn up for me. 



a. External Characters and Tterylosis* . 



The nostrils are situated nearer the upper than the lower margin of the mandible. Their 

 apertures are oval, or slightly sigmoidal in shape. They have a well-developed operculum, but 

 are left uncovered by the frontal plumes. Behind each are a few large and conspicuous, 

 forwardly-directed bristles, the most anterior of the rictal series. The eyelids, both upper and 

 lower, have distinct eyelashes. The feet [cf. figs. 1-6, e) are feeble, with the hallux (which is 

 absent in the genus Jacamaralcyon) and fourth digit reversed. The tarsi are covered anteriorly 

 with transverse scutellse, which are obsolete in Tlrogalha and Galhula albirostris, whilst behind 

 they are covered with smooth naked skin, along the external aspect of which a few feathers may 

 be prolonged downwards as far as the digits. The second digit is united with the third to about 

 the middle of the second phalanx. 



The oil-gland is always nude, and has a bluntly triangular tip. There are twelve rectrices 

 in the species examined f, the outer pair being much shorter than their fellows, as shown in the 

 figures [infra, pp. xx-xxv, cZ). The wings have 10 primaries, the tenth (or so-called "first") 

 being always abbreviated, and 12 secondaries, the total number of remiges being thus 22. The 

 feathers have a small aftershaft. 



NitzschJ has described and figured the pterylosis of Galhula viridis, and also examined 

 Jacamero'ps. The following description of the pterylosis is based on my examination of Galhula 

 rufovmdis, with which the other species already named agree essentially. 



The tracts are all narrow, generally only two feathers wide. The dorsal tract forms a very 

 slight fork indeed between the scapula, and is here somewhat interrupted, its cervical part being 

 stronger than the more posterior, which has the form of a long fork, enclosing a good median 

 space, and only connected with the former by a few weaker feathers uniserially arranged. The 

 united part of this tract is short. External to this posterior fork are a few smaller feathers on 

 each side, which run in a line backwards towards the acetabulum. The lumbar and humeral 

 tracts are both distinct, but not broad ; the former are quite free from the dorsal tract. The 

 inferior tract starts from the sijmphysis mandibulce, and runs along in the intermandibular space 

 to divide opposite the angle of the jaw, the two halves of the tract remaining thence separate 

 till they terminate just before the vent. Just before getting onto the breast, the tract emits on 

 each side a short, inwardly-directed, " gular " branch, which runs for a short way on the anterior 

 surface of the great pectoral muscle, nearly along the line of the clavicle. When about halfway 

 down the sternum the main tract gives rise to a short, but little divergent, outer pectoral branch, 

 from the end of which a few feathers run uniserially outwards and forwards towards the axilla. 



* The observations subjoined have been made on spirit-specimens of Galhula rufovhidis (two), G. albirostris, and 

 Urogalba paradisea, and on a skin of Jacamerops r/randis. — W. A. P. 



t Only ten in Bracliyrjalha and Jacamaralcyon, the small outer pair being deficient. See below, pp. xxii, xxiii.— P. L. S. 

 + ' Pterylography ' (Hay Soc.'s ed.), p. 90, pi. iv. figs. 7, 8. 



