577 



3480. A partially articulated and incomplete skeleton of a Dromedary (Camelus 

 dromedariud). Mus. Brookes. 



3481. The premaxillary, maxillary and mandibular bones of the right side of a very 

 young Dromedary, showing the deciduous teeth. 



These are : i ^~, c j^, m |^?. The lower canine has a crown more resembling in shape 

 that of the incisors than the corresponding permanent canine presents. The first deciduous 

 molar (d 2) has a simple crown in both jaws ; the second (d 3) and third (d 4) deciduous 

 molars in the upper jaw have each the double pair of crescentic lobes ; the second deciduous 

 molar in the lower jaw has three pairs of crescentic lobes, increasing in size as they are placed 

 further back. 



Genus Auchenia. 



3482. The skeleton of the Llama (Auchenia Llama). 



The vertebral formula is: 7 cervical, 12 dorsal, 7 lumbar, and 4 sacral; there are 13 

 caudal vertebrae, but the terminal ones are wanting. With the exception of the atlas, the 

 cervical vertebras, like those of the Camel, are not perforated by the vertebral arteries in the 

 usual place, but these enter the neural canal and perforate the anterior part of the base of the 

 neural arch on each side. The transverse process is divided into a diapophysis and pleur- 

 apophysis from the third to the sixth cervical vertebrae inclusive, and in the sixth an addi- 

 tional pair of processes is developed from the sides of the back part of the centrum. The fifth 

 lumbar vertebra has the longest spine : the last bone of the sternum is not so expanded as in 

 the Camel. The bones of the extremities repeat the same peculiarities as in the Camel. 



Mm. Brookes. 

 The following, to No. 3487 inclusive, are parts of the same skeleton. 



Presented by the Zoological Society. 



3483. The axis, or vertebra dentata, of a Llama. 



It shows the double perforation of the anterior part of the neural arch for the nerve and 

 vertebral artery. 



3484. The third cervical vertebra of a Llama, vertically and longitudinally bisected 

 to show the position and extent of the canals for the vertebral arteries. 



3485. A fourth cervical vertebra of the Llama. 



The degree of convexity and concavity of the articular ends of the body is much less than 

 in the Camel, and the neck is habitually straighter and carried more erect. 



4 



