200 BUNODID^. 



species, in his admirable memoir " On the Actinias of 

 Falmouth," which was read "before the Cornwall Polytechnic 

 Society", in the autumn of the same year. He had been 

 acquainted with the species ever since 1847 ; and had pub- 

 lished the name in the Society's Report for 1849. To Mr. 

 Cocks's appellation, therefore, belongs the claim of priority ; 

 but even were it otherwise, Mr. Thompson's name must be 

 rejected, not only because it had been previously* applied 

 to another species, but, according to a canon which I have 

 already had occasion to apply to one of my own names,t 

 because it conveys a false idea. The name clavata origi- 

 nated in a misconception. In the single specimen known 

 to Mr. Thompson at that time, he mistook the curling of 

 the tips of the tentacles for a clubbing, whence the name 

 " clavata " — clubbed. These organs have not the slightest 

 tendency to such a form as the term implies. The name 

 which I adopt Avas given, I believe, in honour of the late 

 Robert Ball, LL.D., an eminent marine zoologist. 



I found the species not uncommon at Weymouth in 

 1853, especially on the ledges that are exposed at the 

 recess of the tide, under Byng Cliff. Its habit is to lurk 

 in narrow fissures in the cavities of the under side of large 

 flat stones, and not unfrequently in the deserted holes of 

 PhoJas or Saxicava. The disk is very wide and flat ; and, 

 as it is also very expansile, it spreads itself to a consider- 

 able distance around the margin of its hole. So essential is 

 it to its comfort, however, that it should have a retirement, 

 that if it be put into an aquarium, though it may at first 

 affix itself to a flat stone or to the surface of a shell, it will 

 creep away, by means of its base, till it find some loose 

 stone, under which it will insinuate itself till it is quite 



* M. Rathke had named clavata an Actinia, which he found on the coast 

 of Norway, in 1843. 

 t See ante, p. 75. 



