MEDUSA. In addition to the different species of this genus of vermes described in the Encyclopaedia, that which is represented in two different attitudes, fig. 1. and 2. and which strongly resembles a bagpipe in shape, may be worthy of notice. It is merely a white transparent vesicle, furnished with several blue tentacles yellowish at their extremity; its long tail, which is also blue, appears to be composed of a number of small glandulous grains, flattened and united together by a gelatinous membrane. The upper part of the vesicle exhibits a kind of seam with alternate punctures of three different sizes; its elongated part, which may be considered as the head of the animal, is terminated by a single trunk, the exterior edge of which is fringed with 25 or 26 tentacles, much smaller than those which originate from the inflection of its long tail, and the number of which sometimes amounts to 30. By means of these last, the diameter of which it is capable of increasing at pleasure by forcing in a little of the air from its body, it fixed itself to the side of the vessel, in which it was placed, in such a manner as that the extremity of some of its tentacles occupied a surface of two or three lines from its body. The most moveable part of the vesicle is its elongation, or the head of the animal, as it is by means of this that it performs its different motions. The rounded substance, marked by the letter P, is situated in the centre of the larger tentacles, which are firmly fixed to the body of the animal near its tail; and is only an assemblage of a few minute gelatinous globules, from the middle of which arise other larger globules, with a small peduncle, about the middle of which is fixed a curved bluish coloured body, which is represented magnified in two positions at R. Martiniere, the naturalist, who accompanied Perouse in his voyage round the world, met with this animal in about the 20th degree of lat. and 179° of long. east from Paris.