76 Scientific Intelligence. [July, 



codile, in their general form, in the arrangement of their various 

 processes, and in the suture by which their annular part is at- 

 tached to the body ; they differ, however, in having narrower 

 proportions, in their articulating surfaces being slightly concave 

 on both sides, instead of concave on the one and convex on the 

 other, in bearing the greater number of the dorsal ribs on a 

 single articulating face at the end of their transverse processes, 

 and in the number of dorsal vertebrae, which greatly exceeds 

 that in the crocodile. 



The bones of the anterior extremities are the most interesting, 

 as affording double analogies to the Ichthyosaurus on the one 

 hand, and existing reptiles on the other. The Plesiosaurus ex- 

 actly agrees with the former in the broad, flat, and hatchet- 

 shaped clavicles which distinguish it, but has a distinct humerus, 

 radius, and ulna, in place of the single bone, which, in the Ich- 

 thyosaurus, supplies the place of these three. The paddle forms 

 a very curious link between that of the Ichthyosaurus and sea- 

 turtle ; agreeing with the former in the number of its joints, and 

 the rounded form of the external series of them, but with the 

 latter in the form of all the internal series of phalanges. 



This paper also contains general remarks on the order of fossil 

 remains to which this genus is allied, and, in particular, a re- 

 gular osteological description of the Ichthyosaurus, the most 

 original and interesting feature of which is, a minute examina- 

 tion of the osteology of the head of that animal ; in which the 

 existence of all the bones which characterize that part in the 

 lacerta tribe generally, and in the crocodile in particular, is de- 

 monstrated by a series of careful dissections, and the true place 

 and relations of this animal thus satisfactorily ascertained. 



The principal deviations from the type of the crocodile are found 

 to be such only as naturally arise from the more elongated form of 

 the whole head, and from the bones being applied to each other 

 with a squamous and overlapping suture ; the latter structure, 

 which combines flexibility with strength, being probably de- 

 signed to fit it for residence in the waters of the ocean, as the 

 structure of its vertebral column appears to have been to facili- 

 tate its motions in that element. The method of M. Cuvier is 

 strictly followed throughout these descriptions. 



Article XIV. 



SCIENTIFIC INTELLIGENCE, AND NOTICES OF SUBJECTS 

 CONNECTED WITH SCIENCE. 



I. Succinic Acid. 



M. Julin has favoured the editor with the following notice : 

 The distillation of this acid from amber in the general way produces 

 it in a very small quantity ; by coarsely powdering the amber, and then 



