﻿OSTEOLOGY OF SARCOPS CALVUS. 265 



pelvis of Oriolus chinensis, it is at once evident that the two bones are, 

 morphologically, almost identical. As compared with its length, the 

 width of the pelvis in Sarcops calvus is the mere fraction of a millimeter 

 wider than is the case in 0. chinensis. The same characters also obtain 

 in any of our American orioles, such as Icterus icterus, I. c. sennetti, 

 Icterus spurius, I. galbala, I. bullocki, and others with which I have 

 compared it in this and other particulars. Even as we pass to Euphagus, 

 the pelvis is of the same general pattern, which is likewise true of this 

 bone in its near allies. In Sturnella, the mesial borders of the ilia in 

 the dorso-preacetabular region of the pelvis usually meet the superior 

 border of the sacral crista, a condition I have never met with in any of 

 the other passerine birds named above. 7 It hardly seems necessary here 

 to enter further into details of this bone, as I have so frequently figured 

 and fully described the pelvis of corvine, sturnine, icterine, and related 

 forms of birds, in other papers which have appeared during the past 

 twenty-five years. It has already been pointed out above that there is 

 one less vertebra included in the pelvis of Oriolus than there is in that 

 of Sarcops, but this difference is only apparent after actual count, and 

 in no way affects the general appearance of similarity in the bone in the 

 two genera. 



Coming to the bones of the pectoral arch or the shoulder girdle we 

 find these, too, to be typically passerine in all their characters, and, 

 moreover, remarkably alike in Sarcops and Oriolus. Essentially, too, 

 they are the same in Lamprocorax. We meet with the usual U-shaped 

 os furcula with its conspicuous, oblong hypocleidium extending backward 

 but not coming in contact with the anterior margin of the carina of the 

 sternum in the articulated skeleton. The clavicular limbs are slender, 

 with the usual, expanded, free heads for articulation with the scapula 

 and coracoid upon either side. These last two possess the usual passerine 

 form, and articulate with each other and the furcula, exactly as they 

 do in the Icteridce and related genera. 



At the shoulder joint in Sarcops and Oriolus, and probably in all the 

 other genera mentioned, there is a free, peg-like os humero-scapulare of 

 some considerable size. 



SKELETON OF THE LIMBS. 



There would be but little to be derived from a detailed description of 

 the bones of the pectoral and pelvic limbs of Sarcops, for when it is said 

 that they are typically passerine in all their essential characters, the 

 comparative osteologist at once appreciates what they are like, morpho- 

 logically. As compared with Oriolus chinensis the long bones of the arm 

 or wing are both relatively as well as actually shorter in Sarcops calvus 



7 See fig. 7 of my memoir "On the skeleton of the genus Sturnella, etc. 

 hoc. cit. 



