252 Lamarck's Genera of Shells. 



in an instant all is taken in ; the animal ships his oars, strikes his 

 sails, and upsets his boat, which fills with water and goes down : 

 but when the danger is past, he returns to the surface, bends his 

 sails again, and once more rows gallantly along. 



" The tender nautilus, who steers his prow, 



The sea-born sailor of his shell canoe, 



The ocean Mab, the fairy of the sea, — 

 ******** 



He when the lightning-winged tornadoes sweep 



The surge, is safe — his port is in the deep. Byron. 



Recent observations have vindicated the character of this clever 

 little sailor from the aspersions heretofore cast on it, of being a 

 mere pirate, who having killed and devoured the former inhabitant, 

 seizes on his vessel : they have proved that he is lawful owner, and 

 his own industrious shipwright — and beautiful is the model 

 which his little frail bark is constructed ! It somewhat resemble 

 a nautilus in its external form, whence its trivial name, paper 

 nautilus', but it is essentially different from that shell, iu being 

 unilocular. It is, besides, very thin, externally rugose or tuber- 

 cular, and furnished with a double keel. The end of the spire 

 always turns inwards and enters the cavity, and the last whorl 

 envelopes all the others. The argonautae are found in the Medi- 

 terranean, and East Indies. 



Type. Argonauta argo. (Idem. Linn.) 



Shell large, involute, very thin, white; sides transversely ribbed; 

 ribs frequent, forked on one side ; carinee approximate, tubercular, 

 partially blackish red ; tubercles small, very numerous. Mediter- 

 ranean. PI. vi. Fig. 236. 3 Species, all recent. 

 Section III. 

 Naked Cephalopoda. (1 Family.) 



The animals of this section have no shell, either internal or ex- 

 ternal, but the greater number of them contain a solid, free, cre- 

 taceous or horny substance in the interior of their body. 

 Sepiaria. (4 Genera.) 



This family includes all the animals which Linneus compre- 

 hended under one generic name, sepia ; they are the most perfectly 

 known of all the cephalopodous mollusca, 



