192 MR. H. E. STRICKLAND ON SOME BONES OF 



add to our pre-existing information. I will also append a notice of the single bone in 

 my own possession (No. 17), which has been obtained since the publication of Dr. 

 Melville's chapter on the osteology of the Solitaire. The Nos. used in the list, p. 188 

 supra, are here retained. 



No. 7. Proximal portion of the right humerus of Pezophaps solitaria. The con- 

 formity in size of this fragment to the humerus No. 3, proves that it belongs to this 

 species, and not to P. minor. The perfect state of its surface exhibits several characters 

 which in No. 3 are concealed by incrustation. In its general form it closely agrees with 

 the humerus of the Columhides, but differs in the non-development of the anterior crest, 

 to which the great pectoral muscle is attached. In Pigeons and most birds of strong 

 flight this crest is expanded into a narrow ridge, projecting forwards and outwards, 

 while in this bird we find only an obtusely rounded surface for the insertion of the 

 pectoral muscle. In the incrusted humerus No. 3, the absence of this ridge induced 

 Dr. Melville to suppose that it had been broken off before the bone became incrusted ; 

 but the specimen before us proves that its non-development is a characteristic feature 

 in the structure of the bird. 



As it is the projection of this crest in volatile birds which supplies the pectoral mus- 

 cle with a powerful lever for producing the downward stroke of the wing, and thus 

 sustaining the bird in the air, so we can see the probable reason why in the Solitaire, 

 which we know from historical sources to have been incapable of flight, this ridge should 

 I'emain entirely undeveloped. 



I may add, that the small size of the humerus in this bird is alone sufficient to prove 

 its inability to fly. In the volatile Columbidee we find the humerus to be slightly longer 

 than the femur. Thus in Columba palumbus the humerus is to the femur as 13 to 11, 

 and in Goura coronata as 20 to 17. But in the species before us, the humerus No. 3, 

 which I consider to belong to the same individual as the femur No. 4, is shorter than 

 it in the very considerable ratio of 47 to 73. 



The pneumatic foramen of this humerus is large, and proves that air was admitted 

 into its interior, — a fact, however, quite consistent with inability to fly, as is shown in 

 the case of the Struthio and Rhea, which, though non- volatile birds, yet possess a certain 

 amount of pneumaticity in their bony skeleton. 



The transverse fracture of the shaft enables us to see that its interior cavity is filled 

 towards the upper part with coarsely interlacing cancellous fibres. 



The measurements of this humerus are as follows : — 



inch. lin. 

 Extreme width from the anterior to the posterior crest . . 1 5^ 



Smallest horizontal diameter of shaft 6 



Smallest vertical diameter of shaft 5| 



Horizontal diameter of medullary cavity 4 



Vertical diameter of medullary cavity 3 



