240 



Monography 

 of toiiui&es. 



letkyology. 



Respiration of 

 tb.e ctocudiie. 



SCIENTIFIC NEWS. 



had classed these with his emydes ; noticing at the s^ame 

 time the characters, that distinguish them from all the 

 other species, the shell of which is complete and hard. The 

 large softsbelled tortoise of Bartram Mr. G, places in the 

 genus Chelys of Dumeril. 



Twenty years agt) scarcely thirty species of tortoises were 

 known, but nearly twice as many are accurately described 

 by Mr. Sweiger in his general monography of tortoises. la 

 this wor1v a copious list of syaonimes is given, and it is il- 

 lustrated with figures carefully engraved. 



The class of fishes too has been enriched with many new- 

 species. Mr. Risseau and Mr. Delaroche have communi- 

 cated the observations they made on this subject, the for- 

 mer in the Gulf of Nice, the latter in the sea round the 

 Balearic Islands. It has been supposed, that fishes had 

 their peculiar climates, but Mr. R. has found in the Medi- 

 terranean fishes considered as peculiar to the East Indies, 

 and others known only in the northern seas. Mr. Dela- 

 roche made some interesting observations on the depth at 

 which different fishes habitually live, the manner of catching 

 them, and their airbladders. 



Notwithstanding the difficulty of physiological experi- 

 ments, and the nicety required in them, Mr. von Humboldt 

 made many during his dangerous and toilsome travels. He 

 has communicatt'd his experiments on the respiration of 

 the sharpnosed crocodile of America. He found, that, 

 notwithstanding the volume of its bronchiae, and the struc- 

 ture of its pulmonary cells, it suffers greatly without a sup- 

 ply of fresh air; its breathing is very slow ; and a young 

 one a foot long deprived the air of scarcely 12 cubic inches 

 of oxigenin an hour and forty tbvee minutes. 



To he concluded in our next* 



An accident has rendered us unable to insert our usual Me* 

 teorohgicci Journal this month* 



