1 5 8 SHUFELD T. [Vol. XV 1 1. 



The nostrils are small and oblong ; their height, which is 

 hardly 3 mm., is greater than their width ; they are subvertical 

 in position, with their openings somewhat anteriorly directed. 

 Posterior to the nostrils, the cere constitutes the swelled part, 

 and this, superiorly, develops two tubercle-like elevations. 



The cranium, which is profoundly asymmetrical, is compara- 

 tively large, with orbits of about medium size. 



The asymmetry is present upon both sides, but the left is 

 the more abnormally so. In its structure generally it agrees, 

 perhaps, in so far as the inland species are concerned, most 

 nearly with the cranium of Syrniuni altico, although it widely 

 departs even from it. Its greatest vertical height is at a point 

 posterior to the orbits. Longitudinally the superior aspect 

 of the cranium presents for its entire length a feeble median 

 furrow, which is best marked in the frontal region, between 

 the supraorbital processes. A rather well marked cranio-facial 

 hinge stands between the not very powerfully developed supe- 

 rior mandible and the frontal bones ; this mandibular portion 

 is comparatively short, for, upon being measured from the 

 frontalia, it will enter 2.6 times into the total length of the 

 cranium, provided its horny theca is not taken into account. 

 Posterior to the supraorbital processes the frontal region is 

 rather broad ; the area anterior to the processes rapidly nar- 

 rows as we pass forwards, and it has quite concave borders. 



The asytfi7netry . — The bones that take part in the asym- 

 metry of the cranium are principally the os squamosum, and in 

 a lesser degree the adjacent parts of the frontal, the parietal, 

 and the alisphenoid.^ 



The frontal bones are smoothly and very completely bounded 

 off where they enter into the posterior peripheries of the orbits, 



1 The internal configuration of these bones can only be examined with certainty 

 in the very young. If the individual has arrived at maturity, even if the downy 

 plumage (the first feathers, which are moulted shortly after the bird becomes full 

 grown) is still worn, the sutures among the separate bones have already disap- 

 peared. Although I have made every effort to obtain the young just taken from 

 the nest, I have not succeeded in securing them, having only obtained a pair of 

 indifferent specimens of nestlings, and in these obliteration of the sutures had 

 already partly taken place. So perhaps the above description of the defining of 

 the separate bones in certain instances can be corrected or supplemented. 



