PSITTACID^E.] OSTEOLOGIA AVIUM. [PsiTTACIM. 



Furculum small, short, not reaching to the sternum, flattened obliquely, with a slight 

 process at the junction of the rami. 



Coracoids rather long, with a strong process projecting from the exterior edges just 

 above their junction with the sternum, and with a rounded knob projecting forwards at 

 their junction with the furculum. 



Pelvis rather broad ; the ischium placed nearly perpendicularly to the upper plane of 

 the ilium, the anterior half of the latter scolloped out on the sides; ischiadic foramen 

 large, oval ; obturator very wide for its whole length ; at the junction of the os pubis 

 with the ischium a small blunt spine projects from the latter. 



Bibs projecting far backwards, of moderate strength ; the styliform processes short and 

 broad. 



Wing-bones short and weak ; metacarpal bones anchylosed together at both extremities, 

 posterior one much arched; scapula bent downwards to a point and flattened at its 

 extremity. 



Femur with the trochanters small ; tibiae above twice the length of the metatarsus ; 

 fibulee half the length of the tibiae, not anchylosed to the latter for the first half of their 

 length. Entometatarsal bone elevated into a ridge in front ; the two other bones form- 

 ing the metatarsus projecting backwards behind it, and having a channel between them ; 

 calcaneal process extending over the whole width of the metatarsus, and slightly excavated 

 in the centre. Vertebral column of moderate strength ; the penultimate and three next 

 vertebrae with the dorsal spines well developed. 



Measurements. 



Tenths. 



Length of humerus 21 



Length of ulna 26 



Length of metacarpus 15^ 



Length of femur 19 



Length of tibia 25 



Length of metatarsus 9 



Length of sternum 25 



Tenths. 

 Breadth of posterior margin of sternum 14 

 Breadth of anterior margin of sternum 12 



Depth of keel 9 



Length of head ....... 29 



Breadth of head 12^ 



Length of pelvis ...... 26 



Breadth of pelvis . . . ... 13 



Illustrations. 



Base and section of cranium, Plate XI. 

 fig. 1. 



Sternum, coracoid, scapula, furculum, pelvis, 

 and metatarsus, Plate X. fig. 1. 



Psittacus, Linn. 



Melanocephalus, Linn. 

 Cranium with the antorbital process extended backwards, so as to meet the cranial 

 portion of the sphenoid, to which it is anchylosed, thus completing the bony ring round 

 the orbits ; in other respects the cranium is similar to that of P. erythacus. 



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