10 



Guide to the Invertehrata, 



Cuttle- fleshy, and in part is armed with lingual teeth similar to those 



^ ®^" of the snail and whelk. The eyes, except those of Nautilus, 



6ALLEKY <j ' i- > 



yjj_ are large and brilliant, and highly developed, resembling those of 



the higher vertebrate animals. 



Fig. 23. — Part of the radula of 

 Sepia officinalis, Linn. (Magnified.) 



Fig. 24.— Part of the radula of 

 Octopus vulgaris, Lamk. (Magnified.) 



Although the Cephalopoda seem, at first sight, so different from 

 the other members of the molluscan class, they nearly all possess 



Fig. 25. — [a) Internal shell and {b) 

 animal of the squid, Loligo media, 

 Linn. British coasts. (Reduced.) 



Fig. 26. — Front and side-view of 

 internal shell, or sepiostaire, of the 

 common cuttle-fish, Sepia officinalis, 

 Linn. British coasts. (Reduced.) 



a shell (or the rudiments of one) — sometimes external, as in the 

 Pearly Nautilus, Fig. 19, but more frequently internal, as in the 

 squids and cuttle-fishes (Figs. 26 and 27) — which serves to 

 protect the more delicate organs of the body, and corresponds 



