Oriolid^;.] 



OSTEOLOGIA AVIUM. 



[IcTERINJS. 



Measurements. 



Tenths. 



Length of humerus 10 



Length of ulna 11 



Length of metacarpus 5 



Length of femur 9 



Length of tibia ........ 15 



Length of metatarsus 10J 



Length of sternum 10J 



Tenths. 



Breadth of posterior margin of sternum 6 



Br eadth of anterior margin of sternum 6 



Depth of keel 3 



Length of head 17 



Breadth of head • 7 J 



Length of pelvis ...... 10 J 



Breadth of pelvis 7| 



Quiscalus, Vieill. 



Major,. Vieill. 

 The form of the skeleton of both the above bird and Quiscalus crassirostris are not 

 distinguishable except in size from Cassicus. 



Illustrations. 

 Sternum, pelvis, and metatarsus, Plate XVIII. 



Agelaius, Vieill. 



Chopi, Bp. 

 Very similar to Icterus, but has the posterior sternal fissures more open, the manu- 

 brial process longer, and the keel deeper ; the hinder part of the sternum also wider 

 than the anterior, and the metatarsi longer in proportion to the tibia. 



Ploceus, Cuv. 



Erythrops, HarL 



Cranium rounded, with a depression at the base of the lower mandible ; deep nasal 

 septa, with two small foramina. Palatine bones similar in form to the Sternid<e, but 

 shorter, and with the lateral processes more developed. Occipital ridge well marked. 



Sternum similar in form to the Stumida, but with the apex of the keel receding, and 

 the plain of it being broader in proportion to the length. 



Bibs similar to Sternidce. 



Furculum similar to the Sternidte, but with the process at the junction of the rami 

 turned more abruptly upwards, not touching the sternum. 



Coracoids long, nearly as long as the sternum. 



Scapula longer than the humerus, slightly expanded towards the tip. 



Wing-bones with the ulna longer than the humerus. 



Vertebral column well developed. 



Pelvis of moderate size, with the ischiadic and obturator foramina rather large. 



Leg-bones not differing in form from other insessorial birds. 

 138 



