FREE MESSMATES. 35 



the Corynes, the Ilydractiniw, and other polyps, while at 

 a later period they frequent molluscs or higher classes; 

 Allman mentions the case of a Phoxichilidium coccineum 

 lodged in a Syncoryne, 



There are, perhaps, many other crustaceans which, 

 placed among messmates, like the Pandarus and others, 

 would have a right to claim a further inquiry. It is a ' l^ 

 fact that they are never seen except on the skin of their "^ 

 host, where they are always visible, preserve their 

 colours entire, and never change their costume for the 

 undress of a parasite. The Pandari live especially on 

 the Squalidse. Some which are found in our seas are of 

 rare elegance of form. We must, perhaps, place among 

 messmates the crustacean which Siebold found in the 

 Adiiatic, at Pola, on the belly of the worm Sahella 

 ventilahrum, and it is not impossible that the Staurosoma 

 observed by Will on an actinia, should have its place 

 here rather than among the parasites. 



A Eotifer without vibratory ciHse, the Balatro calvus 

 of Claparede, lives as an epizoon on the same anneUds 

 which lodge the Albertia in their interior. The Dar- 

 winists, observes Claparede, will not fail to remark the 

 presence of these Kotifers of the genus Albertia in the 

 interior of the animal, and of the genus Balatro on the 

 exterior. The parasite Balatro, like a shadow, never 

 quits his Mecaenas, says the learned naturalist of 

 Geneva; who has observed it on the limicolous Ol'igochxts 

 of the Seime, in the Canton of Geneva. 



The Nehalia of Geoffroy is an interesting crustacean, 

 abundant on the coast of Brittany. This charming 

 animal gives lodging habitually to a messmate which 

 Mons. Hesse considered as an animal allied to the 



