DR. J. MURIE ON THE ANATOMY OF THE SEA-LIOX. 553 



upon the sides of the trachea close behind (below) the cricoid cartilage and immediately 

 adjoining the oesophagus. Each gland is of a narrow elongated form, about If inch 

 in length, and - 4 inch wide at its broadest part ; it extends from the first to the sixth 

 tracheal ring. Anteriorly what may be considered the head or broader end is roundish, 

 or well defined ; but posteriorly the gland mingles with the thick layer of yellow elastic 

 and fibrous tissue (deep cervical fascia), which encompasses the trachea and connects it 

 with the oesophagus as well as with the vessels of the neck. The surface of the thyroid 

 body is smooth, and of a yellowish or orange colour ; section demonstrates its substance 

 to be compact, with only a few vascular channels on its oesophageal side. There is no 

 fibroid or muscular band representing a levator thyroideae. 



As regards thymus gland, no remnant of this fcetal organism was noticed. 



VI. The Digestive System. 



1. Parts and Organs wit hin the Mouth. 



a. The Teeth and Palate. — In this male animal the dentition presented the normal 

 number accorded to the adult of Otaria, the formula being 



T 3—3 r , 1—1 -r, 4-4 ,, r 2—2 „,, 

 I. g=2' C - 1=1' Pm - 4=4' M - 1=1 = 36 - 



The hard palate is as usual covered by firm periosteum, and by a lining of mucous 

 membrane of a pale tint ; but these are only of moderate thickness. The openings of 

 the anterior palatine canals are two long slits placed nearly behind the incisor teeth. 

 They have an antero-posterior direction 0T5 inch apart in front, and diverge slightly 

 from before backwards. The front portion of the palate to as far back as the 

 anterior premolars is tolerably smooth. From between the premolars backwards to 

 about opposite the hindermost molars, there is a series of transverse ridges. These 

 elevations are low, and somewhat flat on their summits. The most of them do not 

 traverse entirely the palate from one side to the other, but are irregularly interrupted 

 in the median line. Each half slants inwards and backwards in such a manner that if 

 continuous they would form a series of low arches, the convexity of which is directed 

 backwards. The interspaces or hollows are less than half the breadth of the raised 

 portions of membrane ; and the median longitudinal one is somewhat wider than the 

 transverse ones, especially as it meets these. Behind the teeth the surface of the palate 

 is smooth. 



b. Lingual Organ superficially considered. — The tongue in Otaria jubata is a thick 

 fleshy body, which dorsally at the root is greatly arched both transversely and longi- 

 tudinally, and becomes somewhat flatter towards the narrower anterior bifid extremity. 

 Looked at laterally, when it has been removed from the mouth, it presents an elongated 

 wedge-shape, with roundish margins. A marked lateral row of large papillae defines 

 the smooth under surface from the opposite upper roughened dorsum. As seen above, 



