﻿April, 1857.] 



ELLIOTT SOCIETY. 



17$ 



medusae of the third size, are few in number and situate only at 

 the extremities of the ultimate twigs of the cluster. These are 

 decidedly shorter than those of the second size, but their breadth 

 is proportionately greater, and their general appearance decidedly 

 different. They are of companulate form, the bell-wall being 

 very thick and transparent. Their attachment to the twigs is not 

 by means of a slender pedicle as in most fixed hydroids but by a 

 very broad transparent neck equalling at its origin the width of the 

 medusa-bell and gradually lessening in diameter until it merges 

 into the twig. In fact, the general form of this medusa reminds 

 one of the form of Forbes' genus, Steenstruppia, with the excep- 

 tion that the conical part above is much greater in proportion to 

 the depth of the bell. Below in the neighborhood of the bell- 

 margin, the bell-wall has the same appearance of being suddenly 

 sloped off towards the origin of the vail as in the above-mentioned 

 genus and Euphysa. I did not make out the vail. The digest- 

 ive trunk appears to be so enlarged by the developing sexual 

 organ as entirely to fill the bell-cavity. The whole bell and its 

 cavity excluding the conical part which connects it with the twig 

 of the main stem, presents an almost quadrate form, the longitudi- 

 nal diameter being but slightly greater than the transverse. I 

 can scarcely say that I have made out any difference of character 

 between these latter sexual medusae and those of P. Olfersii 

 figured by Gluatrefages. I am inclined to think, however, that 

 in our own species the longitudinal diameter is greater in propor- 

 tion to the transverse than in the Rochelle specimens. We must 

 now speak of the coloration of this community, which in in- 

 tensity, beauty, and variety, is certainly equal to that of any other 

 object in nature. The general color of the basal bladder-like 

 medusa is a blue, rather light but sufficiently deep to make the 

 bladder very conspicuous when thrown on the yellow sand of a 

 beach. This blue is not pure but mixed with a certain proportion 

 of rosy pink, which is so small in the middle portion of the bladder 

 as to be only seen in certain lights, when it gives a slightly pur- 

 plish tint to the blue. Towards the extremities of the bladder this 

 pink increases in quantity and intensity, and both of the very ex- 

 tremities are characterized by it. The pore, however, is of a blue 

 color somewhat deeper than that of the bladder-walls. The ground 

 color of the crest is also blue, but along its upper edge it is 

 characterized by a pink like that of the extremities. Beneath, 

 this pink passes into vermillion which is prolonged downward in 



