LONG-NECKED SEA-LIZARDS. 



93 



planted in distinct soo 

 kets, instead of being 

 arranged in a continu- 

 ous open groove. In 

 the latter respect the 

 creatures under con- 

 sideration resemble cro- 

 codiles, and no other 

 existing reptiles. 



In the chapter on 

 Fish-Lizards a woodcut 

 (Fig. 24) of one of the 

 joints of the back-bone, 

 or vertebra, shows that 

 these are very short 

 doubly -concave disks, 

 and in the region of the 

 back carry two small 

 facets on their sides, 

 with which the forked 

 heads of the ribs are 

 articulated. Moreover, 

 the upper part of each 

 vertebra, forming the 

 arch through which the 

 spinal marrow runs, is 

 completely separated 

 from the body of the 

 vertebra (the only part 

 shown in the figure), 



