Falconid^e.] 



OSTEOLOGIA AVIUM. 



[MlLVIN^E. 



portion to its width ; the space between the upper margins of the orbits much less. 

 Lacrymals wanting. One large orbital foramen in the centre of the septum, and two 

 smaller ones posterior to it. 



Foramen magnum rounded above, but with the lower side nearly straight. Atlar 

 tubercle oval. Palatine bones of similar shape to those in Falco, but rather broader. 

 Nasal orifices triangular, with the angles rounded. 



Sternum convex, with two small foramina on the posterior margin; small pectoral 

 muscle impression very distinct ; keel more arched on its inferior edge than in Falco, 

 receding anteriorly, and not prolonged to the posterior margin of the sternum. 



Pelvis much broader anteriorly in proportion to its posterior diameter than in Falco. 



Bibs similar to Falco, but not so strong. 



Metatarsus with the calcaneal process well developed, but without any elevated rib 

 proceeding downwards from it. The entometatarsal flattened, broad, forming a keel on 

 its inner edge, 



Remaining bones very similar in form to Falco, except in proportional measurements. 



Measurements. 



Tenths. 



Length of humerus 48 



Length of ulna 57 



Length of radius 53 



Length of metacarpus 27 



Length of femur 27 



Length of tibia 34 



Length of metatarsus 20 



Length of sternum 30 



Tenths. 

 Breadth of posterior margin of sternum 17 

 Breadth of anterior margin of sternum 16 



Depth of keel . 5^ 



Length of head 31-^ 



Breadth of head 17 



Length of pelvis 35 



Breadth of pelvis 16 



Illustration. 

 Sternum, Plate III. fig. 7. 



Elanus, Sav. 



Melanopterus, Laud. 



Some fragments obtained from a skin and a body in the British Museum are all I 

 have seen of the bones of this bird. 



The cranium is similar in shape to Milvus, but with the palatine bones broader and 

 the exterior hinder angles more rounded. Metatarsus similar in shape. The sternum 

 short ; the keel not reaching to the posterior margin, which is perforated by two small 

 foramina, and slightly excavated in the centre ; the inferior edge of the keel but slightly 

 arched. 



Furculum much arched for its anterior third, then nearly straight to the sternum. 



