150 Mli. \\. V. PWIt.UT ON THE USTEUl.UfiV j Ffli. 20, 



the jiroforacoid turns downwards to fuse with the inturned portion 

 of the aerocoracoid, tlius entirely suriounding tlie foramen in 

 question. To the outer side of this jiroeoracoid band tht^ 

 expanded free end of the furcula is attaclied, tlie dorsal border of 

 this exi)ansion fitting into a trianj^ular notch in the free edge 

 of the acromion process of the scapula : this acromion process, 

 by the way, being set on in advance of the procoracoid band, 

 serves to further increase the length of the roof of the foramen 

 triosseum befoi-e refeii-ed to. 



In the PittidiB the procoracoid process is wanting : the roofing 

 of the triosseal foramen is consequently furnished entirely by the 

 acromial process of the scapula, while its inner wall is formed 

 l)y the expanded foot of the furcula. This rests against the 

 acrocoracoid and altogether in front of the acromial process, 

 which, however, it touches by its posterior dorsal angle, and then 

 completes the triosseal foramen. 



Jn the PhilepittidiB the procoracoid is moderately well developed 

 and tui'ns abruptly downwards, so as nearly to meet the acro- 

 coracoid, the gap being tilled by a ligament. The aciomion of 

 the scapula crosses the coracoid, so that it lies immediately over 

 the anterior boi'der of the procoracoid. The upper end of the 

 expanded foot of the furcula is attached, partly to the acrocoracoid, 

 and partly to procoracoid and acromion of the scapula, forming 

 an extensive attachment with its anterior face. 



Tn the Piprida? the procoracoid lies immediately behind the 

 acromial of the scapula and the expanded foot of the furcula ; 

 attached in front to the aci'ocoracoid, and behind to the scapula, it 

 closes in the triosseal foramen, the actual roof of which is formed 

 entirely by the scapula, the procoi'acoid forming a sort of pent- 

 house continuation of the roof candad of the scapula. This 

 arrangement agi'ees with Avhat obtains in the Eurylsemida^ the 

 remaining groups here dealt with, and the higher Passeres. 



vi. The Pelvic Girdle. 



The pelvic gii-dle differs considerably among the families here 

 iinder consideration, the more primitive types showing a rather 

 close resemblance to the Euryhvmidte in this matter. 



In Fhilepitta this resemblance is fairly close, especially in so 

 far as the post-acetabular region of the innominate is concerned. 

 In front this element takes the form of a concave, conical blade, 

 which does not rise to the level of the neural spines of the 

 synsacrum, and is set oif therefrom by the transverse processes of 

 the enclosed vertebrte ; behind the acetabulum the innominate 

 expands to form a broad dorsal plane, which terminates caudad 

 in a point opposite the transverse process of the third caudal 

 vertebra. There is no pectineal process. The ischium is con- 

 tinued backwards and downwards in the form of a narrow curved 

 blade, terminating in a truncated point bent shai'ply upon the 

 main body of the blade, thus ser\-ing to create a wide isehio- 



