PODOCORYNE CARNEA. 3] 



fills in the meshes, and is set at intervals with spines ; 

 and (3) as a continuous crust bristling with spines. 



These facts are interesting, not only as clearing up the 

 discrepancies in the accounts of the species, but as throwing 

 light on the formation of similar structures. 



The polypites of P. carnea vary in colour ; they are 

 sometimes white or with a slight tinge of yellow, and 

 sometimes reddish. The proboscis is always opake white, 

 and at the base of it there is often a collar of deeper red. 



There is no constant and uniform difference in size and 

 the number of tentacles between those which bear the 

 reproductive bodies and those which do not. Commonly 

 the prolific polypites are smaller than the rest, and are 

 sometimes much dwarfed and attenuated, the number 

 of arms being reduced to 4 or 5. But they occur with 7 

 or 8, 10, and even 16, and are not unfrequently fully 

 developed in all respects. 



The gonophores are produced in large clusters, forming 

 a collar round the body of the polypite, some distance be- 

 low the tentacles. I have counted 6 in a group; and Sars 

 gives the number at 811. 



At the time of liberation the four tentacles, which are a 

 continuation of the radiating canals, are fully developed, 

 and there is generally a smaller tentacle in the centre of 

 two of the interradial spaces. Two more soon bud from 

 the remaining spaces, so as to make the whole number 

 eight ; but 110 further increase has been observed. 



The mouth is divided into four distinct lobes, each of 

 which is furnished with a tuft of thread-cells. These are 

 mounted on extremely delicate peduncles ; and when the 

 mouth is in search of food they are brought into an erect 

 position, and are in constant vibratile motion. 



The gonozooid swims by a series of jerks or casts, and 

 carries the arms curled back over the bell. 



