Vitalitij of Sponges. — Plesiosaurus. 287 



Plants, as well as lie did Corals, &c. has in his chapter on Sponges 

 this curious observation, which proves quite the contrary. " J'ai 

 un fond suffisant de ces plantes pour en faire une botanique entiere, 

 & plusieurs reflexions curieuses sur la systole & diastole, que 

 j'ai observees, dans certains petits trous ronds de ces plantes, 

 lors qu'elles sortent de la mer, mouvement qui dure jusqu' d ce 

 que I'eau soit entieremcut consumee." 



PLESIOSAURUS. 



Of the Saurian reptiles, the remains of which abound in the 

 secondary strata in this country, the Plesiosaurus is unquestion- 

 ably one of the most interesting ; we are informed that several 

 skeletons of this extraordinary animal have been taken up lately ; 

 one of them in so perfect a state as to enable Mr. Conybeare to 

 determine with a certain degree of precision the general form 

 and characters of the skeleton of the animal : we shall only now 

 mention the great length of its neck, in consequence of the extra™ 

 ordinary number of cervical vertebrse, amounting, perhaps, to 

 forty, a number far exceeding any thing that has hitherto been 

 observed in any class of animals. 



