the genus Comatiila. 299 



wards. Mr Millar, in his laboured but excellent work on the 

 Crinoideae has figured our comatula in this stage as a new spe- 

 cies, under the title of C. fimbriata ; indeed, no naturalist who 

 had not investigated their habitudes in their own element, and 

 at all seasons, could possibly arrive at the knowledge of this 

 very remarkable and curious piece of economy, which may be 

 considered as unique. These animals are further distinguished 

 by the peculiarity of having two openings to the intestinal canal, 

 by which they also differ from the rest of the asteriae. 



The great abundance of comatulae, in the places they inha- 

 bit, is not to be wondered at when we are aware how exceed- 

 ingly prolific they are ; thus each arm may be estimated to bear 

 thirty fruitful conceptacles, each producing about a hundred 

 ova, and as there are ten such, this gives 30,000 ! as the amount 

 of ova produced by a single individual. 



Connected with the natural history of the comatula is that of 

 a nondescript parasite, which appears to be a complete zoologi- 

 cal puzzle, as it is not possible to determine from its figure and 

 structure to what class it ought to be referred. This little ani- 

 mal is figured at Figs. 9 and 10, much magnified, its natural size 

 not exceeding that of the breadth of the ossicula of the arms of the 

 comatula ; it resembles a flat scale, runs about with considerable 

 vivacity on the arms of the animal, and occasionally protrudes 

 a flexible tabular proboscis, ending in a papillary margin. The 

 disk or body is surrounded by eighteen or twenty retractile and 

 moveable tentacula, and beneath is furnished with five pair of 

 short members, each ending in a hooked claw. Query, Is it a 

 perfect animal or a larva, and does it belong to the Crustacea, 

 Annelides, or what ? 



Explanation of the Figures in Plate II. 

 Fig. 1. Pentacrinus europaeus, a group of the natural size. 

 Fig. 2. The same magnified ; ff the basis ; e and d, two individuals 



in early stages of growth ; a, 6, c, fully developed individuals. 



At X letter a the vent is seen, and below it the valvular mouth 



of the animal. 

 Figs. 3 and 4. An individual of the natural size, and magnified, still 



more developed, beginning to form pinnae towards the ends of 



the arms, as at a, 6 ; in this the cirri or claspers at the back of 



the animal are very distinctly seen. 



