240 Description of the Chlamyphorus truncatus. 



there exists a considerable concavity between them, which, in 

 the recent state, was filled with an adipose, gristly mass, 

 which served to unite the skull to the plates above. The 

 snout commences anteriorly to these processes, and is rapidly 

 attenuated and depressed. The ossa nasi are broad and 

 strong, slightly arched transversely, extending anteriorly be- 

 yond the os incisivum, as does likewise the osseous septum 

 narium. The zygomatic processes are laterally arched ; a 

 small pointed process, descending near the malar bone, (some- 

 what like that in the sloth) ; the zygomatic fossae are large. 



The labyrinth is protuberant, and occupies the usual situa- 

 tion at the base of the skull ; joined to which is the tympa- 

 num • — to the last is attached a bony cylinder, stretching first 

 upwards behind the zygomatic process of the temporal bone, 

 around which it makes a, sudden curve, and runs forward and 

 upwards to terminate at the external ear. This structure, which 

 I believe is peculiar to the animal before us, will be better un- 

 derstood by referring to the plate. 



Lower jaw. Anterior portion shaped like that of the ele- 

 phant, much elongated ; the general form and proportion re- 

 sembles very closely the lower jaw of the sheep, the base being 

 considerably arched, and the curve at the posterior part, form- 

 ing with the base nearly a right angle, projecting obliquely 

 outwards : the base is marked by eight slightly elevated pro- 

 tuberances, occasioned by the roots of the teeth ; the condyloid 

 process is longer than the coronoid ; in the sheep, this is re- 

 versed : the articulation at the glenoid cavity is such as to 

 admit of great freedom of motion. Length of the base of the 

 lower jaw one inch ; length of the angle five tenths ; greatest 

 width two and a half tenths ; width of the angle three tenths. 

 Teeth. Incisors, none in either jaw ; molars, eight in num- 

 ber, on either side of the upper and lower jaws, all approxi- 

 mate ; disposed in separate alveoli ; the crowns of the two first 

 only, approach to a point, and thus much resemble canine 

 teeth ; the six remaining are all nearly flat on the crowns ; 



