348 Structure of the Fossil Saurians. 



and left. The chevron bone is anchylosed to the vertebrae # , 

 which is referable to no existing reptile, but rather to fishes. 

 The question might here be asked, Does this chevron bone pre- 

 sent anything of that fish-like character which is found par- 

 ticularly in the hinder surface of the inferior spinous process 

 of some other fossil Saurians? In the middle of the back the 

 vertebras want those processes which this creature has in com- 

 mon with the Dolphin. The ribs are inserted only by means 

 of the head. The total amount of the vertebrae is 133 ; and 

 the whole length of the animal (without the atlas and the 

 axis) measures 6*59 metres. It is further peculiar to this 

 creature, that many of the caudal vertebrae are entirely desti- 

 tute of any inferior process at their base. Hence, it is probable 

 that the tail in this part was cylindrical, and was only extended 

 to an oar-like shape at some distance from its base. The ribs 

 are round, similar to those of the Lacertae ; and the scapula 

 appears to have possessed some similarity to that of the 

 Lace"rtae. The os pubis very much resembles that of the 

 Monitor. Of the long bones of the limbs none have yet been 

 found. The hands and feet appear to have been adapted for 

 swimming more or less, like those of the Dolphin or Plesio- 

 saurus. The head measures nearly one sixth, and the tail 

 about one half, of the total length. 



Phytosau'rus Jaeger. \ 

 Dr. Jaeger, in his work on the fossil reptiles of Wirtem- 

 burg, describes several fragments of jaws, which, according to 

 him, belong to a peculiar division of Saurians, named Phyto- 

 saurus. He divides these farther into Ph. cubicodon and 

 Ph. cylindricodon. This animal possessed an elongated 

 beak, similar to that of a Gavial. I therefore assign the nasal 

 orifices to the end of its beak, as in the Gavial. The teeth, 

 with their whole apparatus, appear to him peculiar. The 

 crown of the tooth was, in my opinion, conical. Several teeth 

 so constructed have, indeed, been found. They are long, and 

 their surfaces appear as if they had been occasioned by grind- 

 ing. This supposition is rendered very probable by the com- 

 pressed situation of the teeth in the jaw. The teeth are not 

 placed like pegs in an alveolus, but stand on bases which were 

 probably hollow, or filled with a softer animal substance, which 

 formed the bones of the teeth. In this particular, they re- 



* Two large Saurian vertebrae, from Tilgate Forest, in which the chevron 

 bones proceed from the body of the vertebrtz, are in the Mantellian Museum 

 at Brighton. — Ed. 



f Of this animal, as of others which follow, the limbs have either not yet 

 been found, or have not been satisfactorily made known ; on which account 

 this place has only been assigned to them on supposition. 



