TRANSACTIONS 



OF 



THE ZOOLOGICAL SOCIETY. 



I. 0)1 the Axial Skeleton of the Struthionidce. By St. Geokge Mivart, F.R.S., Sec.LM., 

 Professor of Biology at Universitij College, Kensington. 



Received August 28, 1874. Bead November 17th, 1874. 



In a paper read before the Zoological Society ^ in June 1872, the axial skeleton of the 

 Ostrich was described in considerable detail, that it might serve as a type and standard 

 for future comparisons. The present paper is offered as a first instalment of a series of 

 such comparisons ; and the genera selected are the allied ones, Rhea, Bromatus, Casua- 

 rius, Apteri/x, and Bvnornis, so that a general conception of the axial skeleton as it 

 exists in the Struthionidae may be arrived at. 



It has not been thought desirable here to enter into the same amount of detail as m 

 the description of the typical form, in order not to occupy an undue space in the 

 Society's 'Transactions.' The detailed description of the type, already given, may 

 facilitate further comparisons should they be desired. Rhea, however, appears so 

 peculiar a form as to merit exceptional notice. 



The specimens examined are all in the Museum of the Eoyal College of Sm-geons ; 

 and the illustrations are thence taken by kind permission of the authorities of that 

 Institution. 



THE AXIAL SKELETON OF RHEA. 



In Rhea there are fourteen cervical, and three cervico-dorsal vertebrae (fig. 1, c & cd). 

 There are both three dorsal and three dorso-lumbar vertebrae, the first two of the latter 

 not being ankylosed to the sacrum. To these succeed about nine lumbar vertebrae, all 

 ankylosed together ; and these are followed by three sacral vertebrae, the expanded rib-like 



' See Trans. Zool. Soc. vol. viii. p. 385. 



VOL. X. — PAET I. No. I. — March, 1877. ^ 



