EOLIS. 509 



vents their keeping in action the cilia, which serve for 

 defence as well as for locomotion. Let them cease to 

 move, a regular attack is made, and the animal is 

 soon devoured. It is curious to observe several of 

 these little marauders sporting in the empty shell, as 

 if in derision at the havoc they have made. The 

 Nautilines themselves are mere specks ; what must 

 be the size of the conquerors ? Thousands of young 

 Nudibranchs perish thus early, in a few hours after 

 coming into existence ; indeed, if all came to maturity, 

 our coasts would be literally covered with their 

 multitudes. 



We have already alluded to the beautiful adorn- 

 ments of Eolis (PI. VIII. fig. 14), many species of 

 which are of surpassing elegance. Neither are these 

 creatures by any means such sluggards as many of 

 their congeners, but on the contrary exhibit much 

 violent action, and assume many strange attitudes. 

 While reposing, supine, just under the surface of the 

 water, the tentacula are generally recurved, like ram's 

 horns, and the coloured branchial papillae quietly 

 crossed on the back. Should they, however, be in 

 any way actively employed, were it even in simply 

 taking a glide along the side of the tank, and any 

 interruption or annoyance is suffered, the branchiae 

 bristle up in resentment or defiance. During con- 

 tention for prey, all are in violent agitation, and the 

 vehemence with which both they and the tentacula 

 seem to strike is surprising. The animals also bite 

 each other, and, in short, are amongst the most 

 irritable and contentious creatures that can be ima- 

 gined. During such hostile encounters, the branchiae 



