Cephalopoda. 



51 



Decapoda. Doratopsis, Chiroteuthis, Ommastrephes, and Cranchia 

 (in which the arms are very short and the body is swollen and 

 globular) are among the most striking genera. Some of the 

 abyssal or deep-sea Decapoda are distinguished by the presence 

 of remarkable luminous organs, which are borne on the mantle 

 or near the eyes. In Bathothauma and Toxeuma the eyes are very 

 large and are carried on long stalks. 



Fig. 47. 



Chiroteuthis veranyi (much reduced). 



a. general view of animal ; h. magnified view of pedunculated sucker of the 



terminal club of the tentacular arms ; c. internal shell or gladius. 



The Octopoda have eight arms and the body is rounded and 

 short. The model of a large Polypus punctatus is suspended from 

 the roof of the Gallery. The Paper-Nautilus (Argonauta) is 

 remarkable in that the female secretes a special shell from the 

 two dorsal arms, which serves as a brood-chamber (Wall-case G). 



