VOL. LXXXVI.] PHILOSOPHICAL TRANSACTIONS. 35 



In the upper jaw there are 6 conical incisor teeth, regularly placed ; of these the 

 middle ones are the smallest. Two strong conical fangs, -fths of an inch long, 

 measuring from the edge of the gums ; on each side there are 2 small obtuse 

 pointed teeth, of which that next the fang is much the smallest ; and 1 broad molares 

 with very irregular grinding surfaces. In the lower jaw there are 4 incisores, flatter 

 than those in the upper ; 2 fangs, shorter than the upper ones ; and on each side 

 2 small teeth and 3 molares, similar in appearance to those in the upper jaw. 



The fore legs are short and strong, with palmated feet ; each foot has 5 toes. 

 They are covered with a thick black fur, which has a fringe of the same colour 

 round the edge of the sole of the foot, where the fur terminates. The hind legs, 

 when stretched backwards, reach nearly to the end of the tail, and are well adapted 

 for swimming, having 5 long wide-spreading palmated toes with claws, of which the 

 innermost is the shortest ; they measure across 8 inches, and are completely covered 

 with fur, except a small spot under the extremity of each toe. The claws are of a 

 light colour, and channelled on the under surface ; those on the fore feet. are small, 

 and placed so far back that they seem of little use but as a defence for the upper 

 part of the toe ; those on the hind feet are stronger, and project beyond the toes. 

 The tail is flat, and tapers to a sharp point ; it is covered with a thicker short fur 

 than any other part of the animal. 



A description of the internal parts. — The panniculus carnosus, which lies imme- 

 diately under the skin, is very strong, and extends over the greatest part of the body. 

 The tongue is 4 inches long, and rounded at the end, in which there is a slight 

 fissure, giving the tip a bifid appearance. The papillae on its surface are soft ; they 

 are long towards the root, but less so near the tip. The os hyoides, thyroid, and 

 cricoid cartilages are small for the size of the animal, and weak in their texture. 

 The cricoid cartilage is not a circular ring, but made up of 2 equal parts, united 

 anteriorly ; their lower edge at this union forms an acute angle, the 2 sides pass a 

 little down upon the trachea as they go round it ; and the lower edge laps over the 

 upper annular ring of the trachea. The thyroid gland is small, and divided into 2 

 parts. The epiglottis is short, and its edges are attached by means of a ligament to 

 the inner side of the thyroid cartilage. The passage of the glottis is small. The rings 

 of the trachea are circular, and disunited behind, so that their edges meet, and when 

 pressed on, they lap over each other, being bevilled off for that purpose. Towards 

 the bifurcation of the trachea, the space behind, which is not occupied by the carti- 

 laginous ring, is much increased. This space is occupied by a muscle whose princi- 

 pal fibres are transverse. The trachea is very elastic in a longitudinal direction : 7 

 inches of its length being readily elongated to 10^, and immediately on being left 

 to itself it contracts to its former state. 



The lungs on the right side have 3 lobes, 2 large and one small azygos lobe ; 

 the lower lobe sends a process between the pericardium and diaphragm. On the 

 left side there are 2 lobes. The lungs were completely empty, so as readily to sink 

 in the spirits in which they had been preserved ; the cells are very small, and so 



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