ORCELLA. 373 



patulous orifices occur all over the posterior portion of the organ, and these are the 

 terminations of large racemose glands. The openings are chiefly confined to the 

 hollows between the folds or convolutions. Only filiform papillae occur on the 

 portion of the tongue anterior to the transverse fold, but behind that, as far back as 

 the frsenum epiglottidis, the dorsum is sparsely covered with pedunculated or sessile 

 papillae. The former are club-shaped eminences of the mucosa clad with filiform 

 papillae, and the longest measures about 0*20 of an inch in length, of which its 

 head forms about 0"'10. The sessile papillae are the most prominent, and they are 

 generally situated either singly or in pairs at the mouths of the larger racemose 

 glands, where also but more rarely occur some of the pedunculated kind. 



Palate (PI. XXVII, fig. 1, ^.). — Its surface is triangular, convex from side to 

 side, and perfectly smooth in its anterior or interdental portion. It is thrown into 

 transverse folds behind this in the region of the angle of the mouth, and into 

 longitudinal folds in the remainder of its extent. The interdental portion is, however, 

 traversed by a straight sharp longitudinal furrow, which begins with a bifurcate end 

 embracing a triangular eminence at the anterior margin of the palate. It is deeply 

 marked in the adult and also in the foetus, in which in the region of the transverse 

 folds, it is interrupted by a transverse slit or mucous crypt (^.) situated over the end 

 of the palatal portion of the maxillaries in a line with the inner angle of the mouth. 

 I can throw no light on the nature of this recess beyond that it is lined with the 

 mucous membrane of the palate, which, however, loses its pigment at the margin 

 of the sac. It is 0*40 inch long, and leads into a short cul de sac 0*12 inch 

 in length. The median furrow again shows itself a short way behind the slit and 

 runs backwards for some distance. 



At about 0-9 inch from the anterior margin of the posterior nares in the adult, and 

 0-5 inch in the foetus, there are two crescentic folds of the mucous membrane occur- 

 ring on either side of the mesial line of the palate separated from each other in the 

 adult by an interval of 0*45 inch and in the foetus by an interspace of O"! inch. The 

 convexity of the folds is directed forwards, and each defines a recess in the mucous 

 covering of the palate 0*2 inch in breadth in the foetus, and but only a little larger 

 in the adult. In the left recess of the foetus there is a nipple-shaped structure sur- 

 mounted by a small round sessile papilla, and surrounded at its base by a distinct 

 fold. It is not so well marked on the right side, which is due, however, to the more 

 relaxed condition of the mucous membrane. In the adult when these recesses 

 are laid open they are found to be studded over with small lobules or amygdaloid 

 bodies. The structure, position and contents of these crypts lead to the supposition 

 that they are probably the representatives of the tonsils. If this prove to be the 

 case, they are the first instance on record of the occurrence of these glands in the 

 Cetacea. On the palate, external to and behind the tonsils, are large openings of 

 racemose mucous glands and sessile and pedunculated papillae, the same as occur on 

 the tongue. 



Before leaving the palate, it may be stated, that in the foetus the line of teeth 

 is indicated immediately internal to the groove that defines the palatal surface from 



