CIRCEADiE. 



Genus VII. Circe, Mertens (1838). 



Umbrella coinco-campanulate ; ovaries eight, placed on the sub-umbrella at a 

 little distance around its summit ; vessels eight, simple, passing through the ovaries, 

 and opening into a marginal vessel ; tentacula very numerous, and placed in a 

 single series around the margin ; peduncle cylindrical, contracting near its extremity 

 to form the small campanulate stomach, the orifice of which is furnished with four 

 lanceolate lips. 



Circe rosea^ Forbes (1846). 

 Plate I, Fig. 2. 



The genus Circe was constituted by Mertens for a remarkable little Medusa found by 

 him on the coast of Kamtschatka. Brandt adopted this group in bis ' Prodromus,' and 

 afterwards more fully in the 'Petersburgh Transactions,' where he described the species 

 discovered by Mertens under the name of Circe camtschatica, and engraved it from the 

 drawings of its discoverer. Lesson, in his ' History of the Acalephse,' added two more 

 species to the genus under the names of C. elongata, and C. anais, both discovered by Rang 

 in the African (west ?) seas, and figured from his drawings. 



The Medusa which I now figure and describe under the name of Circe rosea, is the 

 first of the genus noticed in the European seas. Though very small, — the largest specimens 

 taken not being more than half an inch in height, — its aspect is very beautiful and striking. 

 The umbrella is oblong, and somewhat mitre-shaped, with an apiculate summit. The outer 

 surface is quite smooth. Round the margin is a close and single series of small tentacula, 

 which, however, seem capable of considerable elongation, though usually retracted. Their 

 number varies slightly. They are all similar, and in the examples taken, were 56 in number. 

 Their formula might stand as 6x84-8. They are all external to a veil, which guards the 

 orifice of the sub-umbrella, and is marked by sixteen denticulations. I could detect no ocelli at 

 the bases of the tentacula. From the centre of the sub-umbrella depends a long cylindrical 

 peduncle, which reaches nearly to a line with the margin, and is contracted a little above the 

 orifice, so as to form a kind of proboscis terminated by four simple lanceolate lips. The 

 stomach is very short, and terminates almost at the upper point of contraction, where we see 

 eight gastro-vascular canals commence, run up the side of the peduncle, distinct from each 

 other, turn at its base, and descend the sub-umbrella, till they reach and unite with the marginal 

 vessel. In the uppermost part of their course along the sub-umbrella, they pass through as 

 many small ovate, simple generative glands, which, when the animal is seen from above 



