2' Ob-^crvation.'s on the Nafural rlifiUny 



ihenisclves arc so ih'ui that the entire mass of" brain is some- 

 times visible through tlicni. The temporal bones send pro- 

 cesses forward, which articulate with the lower jaw. The two 

 frontal bones are long, and lie nearly in the same plane with 

 tlie iTifra maxillary ; but the cranium is a little depressed^ in 

 tl}at part formed by the parietal bones. Both jaws are fur- 

 i)is])ed with teeth, which are arranged in a beautifully sym- 

 iiietrical order along their respective bordei's. These teeth 

 have a conical figure. In the upper jaw, their number is 

 about 60 ; in the lower jaw there are 70, disposed in two 

 rows parallel to one another. The lower jaw is horizontal, 

 and has no ascending process where it articulates with the 

 temporal bone. 



'i"'he OS hyoides in the proteus is short : its anterior branches 

 extend backwards and outwards, and then bending upwards, 

 proceed to be attached by a large tendon to the sides of the 

 cranium, behind the articulation of the lower jaw * The small 

 arches which sustain the gills are three on each side; the 

 first, or exterior one, is the largest; it is connected anteriorly 

 with the posterior extremity of the os hyoides, by the inter- 

 medium of a little bone : the second, or middle arch, is also 

 furnished with an intermediate bone, w^hich is attached to the 

 intermediate bone of the first arch: the third, or interior 

 arch, has no intermediate bone, but is connected directly with 

 the second by means of a cartilage. The relative size and 

 position of all these parts may be seen in Plate VI. Fig. 1, where 

 the bones of the head, viewed from below, are represented 

 eight times greater than natural. 



From the occiput to the extreme point of the tail there 

 are 59 vertebrae, all of which, except the last, have an osseous 

 structure. Of these, 29 belong to the neck and back, 3 to 

 the sacrum, and 27 to the tail. The first vertebra, or atlas. 



* In the Plates, the animal is exhibited in a reversed positiwi, but in the ana^ 

 tomical descriptions, is supposed to be placed on his four feet ; hence the terms 

 anterior, or forward, look towards the head ; posterior, or backward, towards the 

 tail ; superior, or upward, to the back ; and inferior, or downward, towards the 

 belly of the animal. The terms interior and exterior are used to denote relative 

 nearness to, or distance, from the median line; and those of internal and external 

 lefer simply to the inside or outside of the animal. 



