SAUROPTERYGIA 21 1 



panded end against the almost vertical tympanic pedicle, 

 which gives attachment to the lower jaw. This shows the 

 reptilian compound structure : 29 marks the surangular ele- 

 ment, 30 the angular one, 32 the dentary. In the side-view of 

 the skull in fig. 69, 22 is the premaxillary, 21 the maxillary, 

 15 the nasal — the cavity below being the nostril, 10 is the pre- 

 frontal — between which and 21 is the lacrymal, n the frontal 

 above the orbit. The premaxillary teeth and corresponding 

 premandibular ones are unusually long, strong, and sharp ; 

 there are two similar teeth in each maxillary ; the remaining 

 serial teeth are smaller, but equally acute. There are no teeth 

 on the palate. 



The almost entire and undisturbed vertebral column, from 

 the muschelkalk of Bayreuth, figured by Von Meyer in pi. 23 

 of his work on muschelkalk Saurians, and attributed by him 

 to Notlwsaurus mirabilis, gives the earliest indication of that 

 modification of the trunk-bones which reaches its maximum 

 in the Plesiosaurus (fig. 71), in which it was first detected by 

 the sagacity of Conybeare.* 



Twenty of the anterior vertebras of this series, in Nofho- 

 saurus, which begins with the atlas, have the whole or part of 

 the rib-pit situated on the centrum as in the first vertebra in 

 fig. 69 ; the pit is wholly there on fourteen vertebras ; it begins 

 to ascend upon the neural arch in the fifteenth, as in the second 

 vertebra, given in fig. 69, and is wholly placed there on the 

 twenty-first vertebra. 



According, therefore, to the characters by which the writer 

 has proposed f to distinguish the cervical from the dorsal 

 vertebras, Kothosav.ms has twenty of the former. In the 

 specimen referred to, nineteen consecutive vertebras show the 

 rib-pit supported wholly on an outstanding diapophysis from 

 the neural arch, as in the third vertebra in fig. 69 ; these are 



* Trans. Geol. Soc, vol. vi., 1822, and vol. i., 2d series, p. 381, 1824. 

 f Report of British Fossil Reptiles, 1830, pp. 50, 58. 



