1873.] ANATOMY OF STEATORNIS. 527 



Many points in the osteology of this bird, as well as the descrip- 

 tion of the larynx, are to be found in a paper by Johannes Miiller* ; 

 and further details are given in the works of L'Herminierf, Sclater£, 

 and Murie§. The following notes relate almost entirely to the 

 pterylosis and the anatomy of the soft parts, the skull being only 

 described so far as to make it comparable with those in Prof. 

 Huxley's paper on the classification of Birds||. 



Pterylosis (fig. 1 , p. 528) — All the top of the head is covered with 

 a scattered feathering, which is very much the strongest between the 

 eyes. There is no tendency to the formation of longitudinal bands in 

 this region, like those in the Caprimulgidse. Above each eye there 

 are two rows of closely set very stiff feathers, running parallel to 

 one another and to the border of the upper eyelid, forming a double 

 eyebrow. The upper of these is slightly the stronger ; it is situated 

 \ of an inch above the lower one, with a bare space intervening. 

 The stiff feathers of which it is composed are slightly more than | 

 of an inch long and are directed outwards. The lower eyebrow is 

 -£- of an inch above the margin of the lid, which has no eyelashes 

 and is bare : it does not extend quite so far forward or backward as 

 the one above it ; and its component feathers are not quite so long. 

 The external auditory orifice is nearly circular and -^ of an inch in 

 diameter ; there is no operculum. It is surrounded by a single row 

 of feathers, much like those of the eyebrows ; they are all directed 

 backwards, the anterior being slightly the longer and acting as a 

 protection to the entrance of the ear. Several (about a dozen on 

 each side) stiff simple vibrissse, many more than 1| inch long, spring 

 from the side of the upper beak, and run directly forwards, partially 

 covering the apertures of the nostrils. 



The dorsal tract, where it commences, is narrowed on account of 

 there being a bare space above each ear ; but when it reaches the 

 upper part of the neck it broadens, and continues down the back of 

 the neck as a not strong tract, which becomes narrower and stronger 

 as it descends, till at a short distance above the tops of the shoulder- 

 blades it is very strong indeed. It continues on in this condition, 

 and bifurcates between the scapulae to form a well-developed fork, 

 with long branches, which become considerably weakened near their 

 extremities. Between the lower ends of this fork the continuation 

 of the dorsal tract commences, not connected with it at all, but quite 

 free, as an upward-turned weak arrow-head, situated in the middle 

 line. The axis or shaft of this arrow-headed tract, as it descends, 

 becomes narrower and stronger till it ceases abruptly at the base of 

 the long infundibuliform nude oil-gland, which closely resembles 

 that of the Owls. In the upper part of the loins, above the arrow- 

 head, at a short distance on either side of, and parallel with, the mid- 

 dorsal tract, is a single row formed by four strong feathers, which 

 are distinctly separated from the rest. All over the loins, behind 



* Midler's Arch. f. Anat. 1842, p. 1-11, and elsewhere. 



t Nouv. Ann. du Mus. torn. iii. 1834, p. 321, and elsewhere. 



t P. Z. S. 1866, p. 126. § Ibis, 3rd ser. vol. iii. No. 9, p. 81. 



|| P. Z. S. 1867. 



