﻿OSTEOLOGY OF SARCOPS CALVUS. 263 



existing between the vomer and the prepalatine. There is no osseous floor 

 to the rhinal chamber in front of the vomer — a partition that partly ossi- 

 fies in Oriolus, but not in Stumella. 



At the posterior aspect of the cranium the occipital area is extensive 

 and well defined, while the bounding crest is nowhere raised as it is in 

 the American marsh blackbirds and the genus Stumella — and in these 

 latter forms, too, the occipital area comparatively is not so extensive. 

 All this part of the skull in Sarcops is more as we find it in Oriolus and 

 Icterus. 



Concerning the mandible there is not much to be said, for dt has the 

 usual V-pattern of the^various genera mentioned above, with a moderately 

 deep symphysis and flat sides. As a whole the anterior moiety is bent 

 gently downward, and an elliptical vacuity is to be found at its usual 

 site in either ramus. Posteriorly, the articular ends are truncated, with 

 an indication of a process above, each having the usual intumed one with 

 the minute pneumatic foramen near the extremity. The inferior ramal 

 margins are rounded, while superiorly beyond the symphysis they are 

 cultrate. Upon either side, between the articular extremity and the cor- 

 responding quadrate a sesamoid is to be found. It occurs in the lateral 

 ligament of the jaw, and is very likely to be overlooked in cleaning- 

 skulls of this species for study. 



The sclerotal plates of either eye are small and of about the usual 

 number. They present nothing peculiar beyond what we find in any 

 ordinary passerine bird. This also holds true for the bones of the hyoid, 

 for they possess the usual characters, although we must note that the 

 uro-hyal has a spatulate distal extremity, present also in Oriolus chinensis. 

 In the articulated skeleton, the inferior aspect of the ossified larynx rests 

 Upon this expanded portion of the mesial element of the hyoid. 



REMAINDER OF THE AXIAL SKELETON. 



Sarcops possesses an unusual number of vertebrae in its spinal column 

 as compared with the other genera of birds named above. I find it to 

 agree with the crows and jays, and such genera as MolotJirus and 

 Calamospiza in having 19 free vertebras between the skull and the pelvis. 

 All of the orioles (Icier idee) and the marsh blackbirds which I have 

 examined possess only 18. Sarcops has 11 vertebrae in its pelvic sacrum, 

 that is that portion of the spine coossified with the ilia of the pelvis. In 

 this count it agrees with most crows and jays found in the United States 

 avifauna, orioles and marsh blackbirds (Agelaius, etc.) having but 10, 

 as is also the case with Eupliagus and Stumella. 



Finally, Sarcops has 7 free caudal vertebra? in addition to a large 

 pygostyle. Only 6 tail vertebrae occur in the orioles, and other genera 

 just named. In all these birds they appear to be nonpneumatic, and this 

 also appears to be the case with the several vertebrae, while those of the 



