FEEE MESSMATES. 35 



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

 a later period they frequent molluscs or higher classes; 

 Allman mentions the case of a PhoxichUidium 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 

 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 Squalidm. 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 

 Adriatic, at Pola, on the belly of the worm Sabella 

 ventilabrum, 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 cilise, the Balatro calvus 

 of Claparede, lives as an epizoon on the same annelids 

 which lodge the Albertia in their interior. The Dar- 

 winists, observes Claparede, will not fail to remark the 

 presence of these Eotifers 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 Meesenas, says the learned naturalist of 

 Geneva ; who has observed it on the limicolous Oligochasts 

 of the Seime, in the Canton of Geneva. 



The Nebalia 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 



