CEPHALOPODA. 



39 



tilus, which has a living representative as well as many 

 fossil species. 



Nautilus. Lin. — Shell compressed, convoluted, whorls 

 contiguous, the last enveloping the others; chambers 

 numerous, from 30 to 40, formed by transverse, convex 

 partitions, and perforated by a central siphuncle; inner 

 surface pearly; outer dull, with chesnut brown marks. 

 Animal attached to the shell by two muscles; tentacula 

 numerous (Owen remarks that there are ninety); no arms 

 or suckers, and no ink-bladder ; a pair of large eyes, and a 

 large leather hood, which serves as a covering. — 2 species : 

 also about 100 fossil species. 



Nautilus Pompilius. 



These shells, with their remarkable inhabitants, are 

 found in the seas of warm latitudes, especially those of 

 Africa, Asia, with its islands, and Australia. They are 

 curiously divided by partitions into between thirty and 

 forty chambers, the animal living in the last, but connected, 

 by a flexible membrane running through the siphuncle, 

 with the whole of the chambers. " This series of air cham- 

 bers constitutes an apparatus which renders the Nautilus 



T) 4 



