FEEE MESSMATES. 47 



But of all the Turbellaria, the genus which appears to 

 us the most interesting is the Temnophila, which Gay first 

 observed on crabs at Chili, and which Professor Semper 

 afterwards found on the crabs of the Philippine Islands. 

 Gay and Phillipi found colonies of these animals on the 

 body, the claws, and more especially the abdomen, of 

 the (Eglea. This messmate resembles a trematode by 

 its form and by its posterior sucker, but by its entire 

 character, and especially by its sexual organs, it belongs 

 to the Turbellariw. Mons. Blanchard calls it Temnophila 

 Chilensis. Professor Semper saw at the Philippine 

 Islands these Temnophilaa on river crabs, at five thou- 

 sand feet above the level of the sea. 



The Cydippe densa, a charming polyp of the Gulf 

 of Naples, lodges in its gastro-vascular apparatus larvae 

 of annelids, which may as well be considered parasites 

 as messmates. We owe to Panceri the first observations 

 on these worms, of which two genera, Alciopina and 

 Rhynconerulla, seem to live in the same manner in their 

 youth. A naturalist, whose loss is profoundly deplored 

 by the scientific world, Claparede, occupied himself with 

 observations on these annelids during the last years of 

 his life. It appears that these worms are so common in 

 these polyps, that four have been found at once in the 

 same animal. 



The Spoon-worm, named by (Ersted, Sipunculus con- 

 charum, ought doubtless to find its place here. An oligo- 

 chete worm, Hemidasys agaso, from the Gulf of Naples, 

 lives on the Nereilepas caudata, and Claparede did not 

 think it unworthy of his attention. The surest means 

 of finding it, says this philosopher, is to look for it on 

 this annelid; and our much regretted fellow-labourer 



