234 



CUTTLE-FISH, MOLLUSC A, ETC. 



object, although it gives some trouble through its 

 ink-discharging habits. Besides the above-mentioned 

 species, another octopus (Eledone cirrhosd}, having 

 only one row of suckers on its feet, is kept in most of 

 our public aquaria. 



Fig. 164. 





Sepiola Rondeletii. 



Pen of ditto. 



Although the cuttle-fishes and their allies are un- 

 doubtedly at the head of the mollusca a position 

 warranted by their specialised and perfect organs of 

 sight, brain (enclosed in a cartilaginous box, sug- 

 gestive of a skull), mouth, stomach, locomotive powers, 

 &c. they belong to one of the most ancient groups, 

 geologically speaking. We meet with some of their 

 ancestors in the Cambrian strata ; although the recent 

 type of cuttle-fish, with the hard parts internal in- 



