﻿April, 1857.] 



ELLIOTT SOCIETY. 



145 



each with five spots, which, appearing- as one to the naked eye, 

 contrast strongly with the fleshy white of the polyps and give 

 them a spotted or wharty appearance. The central polyp is, as 

 usual, flask-shaped or funnel-shaped, and presents no distinctive 

 character from those represented for other Porpitse, or none which, 

 without a direct comparison of the animals, I could seize. Its base 

 is in width about one-fourth part the width of the disk. The 

 mouth capable of such expansion as to equal the base in width, 

 but according to my observation this only occurs when the polyp 

 is contracted lengthwise, so as to lose altogether its polypoid ap- 

 pearance and assume the form of a mere fold around the centre of 

 the disk's lower surface. The silvery white air-shield is marked 

 as in P. coerulea Esch., with little tubercles or denticles, but 

 they are according to my observation few in number and scat- 

 tered, or rather occurring at rare and irregular intervals along 

 the course of the radii. The shining silvery appearance is 

 given to the shield by the presence of the air-bubbles in the mul- 

 titudinous inter-communicating cells within. It is lost, when, at 

 the death of the community the air disappears and the whole 

 polypidom sinks to the bottom. 



The border of the disk is not blue, strictly speaking, but a 

 bluish green ; there is little or no pure blue about the polypidom, 

 that I can find. The stem of the tentaculiform individuals is of a 

 pale transparent tint of yellow, and the knobs or buttons along 

 its sides are of a green, rather bluer than that of the body. The 

 medusa-bearing polyps are all of a fleshy white, as is also the 

 central polyp. The color of the medusa-buds which appear to 

 spot the polyps is. to the naked eye, a kind of reddish brown. 

 The medusa-bearing polyps near the tentaculiform individuals are 

 not blue, as stated by Eschscholtz to have been the case in P. 

 coerulea. I have taken these animals only twice at an interval of 

 nearly four years. The last time finding only a single specimen. 

 They are not inhabitants, but only transient visitors of Charleston 

 harbor, and appear there only after a prolonged southeast or south- 

 erly gale lasting several days, when large numbers of Physaliae 

 and this Porpita are brought in and thrown on the beach of Sulli-' 

 van's Island. When obtained, consequently by me they were 

 always more or less injured, principally in the border and the 

 marginal individuals, which latter are so easily detached as to 

 render it difficult or almost impossible to transfer the community 

 to a vessel of water without depriving it of nearly the whole of 



