ORGAN OF SMELL IN MAMMALIA. 211 



by the surrounding air sinuses, which pervade every bone of the 

 cranium. Tin; bony nasal passage is continued in almost ;i 

 straight line from the anterior aperture, a, to the posterior one, 

 h. The vomerine part of the septum, 13, extends from the pre- 

 sphenoid about half-way to the anterior aperture. At the upper 

 part of the cavity, so divided, the ethmoturbinals are situated, 

 which are moderately plicated : the maxillary turbinal is, .also, 

 comparatively simple in character. 



In the Tapir the shorter proboscis terminates by a small 

 pointed extremity between the nostrils. The snout is covered 

 with hair to the base of the terminal appendage ; the hair on the 

 upper part tending upward or backward, that on the sides toward 

 the tip. The cribriform plate is not simply perforate, but is re- 

 ticulate, with long radiating meshes, the latter closed by dura 

 mater : it sends down curved lamella?, sheathing the olfactory 

 nerves. The ethmoturbinal consists of as many convolute divi- 

 sions attached to, or continued from, those processes, in a pedun- 

 culate way ; and each is perfo- 

 rated by many foramina through 

 which branches of the olfactory 

 pass to the pituitary membrane. 

 The maxillary turbinal is elon- 

 gate and simply convolute. 

 The nasal cartilages show the 

 chief modification, the alar 

 portions, fig. 155, w, being 

 continued backward, expand- 

 ing, and filling the peculiar 

 grooves of the skull (vol. ii. 

 p. 449) between the nasal bones 

 and orbits, o : here the cartilages are semiconvolute, convex, and 

 entire outwardly, excavated on the inner side, the cavity beino- 

 continued by a groove into the nasal one at the sides of the outer 

 aperture : from the character of the lining membrane, it may be 

 regarded as an extension of ( Jacobson's fossa.' The f levator 

 rostri,' or raiser of the short proboscis, fig. 155, a, arises from the 

 process of the lacrymal, runs in a fibrous sheath, converging to 

 its fellow, and is inserted into the upper or fore-side of the part 

 which, together, they raise, or, acting separately, draw to their 

 own side. A broader muscle, ( retractor labii,' b, from the same 

 origin expands to its insertion at the side of the labial part of the 

 base of the proboscis. Beneath this is the muscle, c, which 

 rising from the lower border of the lacrymal, spreads upon the 



p 2 



Alinaea] cartilage («) ami muscles of trunk, Tapir. 

 XCIIl". 



