CYAN^A. 77 



Genus Chrysaora, Peron. 



4. The Medusa fmca and M. tuherculata of Pennant, described by him after Borlase, 

 are varieties of the animal called Medusa hysoscella by Linnaeus, and belong to the genus 

 Chrysaora of Peron. The umbrella is hemispherical and expanded ; its margin is festooned, 

 and furnished with more than eight tentacula. The arms beneath are long, simple, and all 

 separate ; the mouth is centrally in the midst of their bases. Four openings conduct to the ovaries. 

 Our 'British species has a yellowish or reddish disk, marked with more or less distinct pale 

 rays, and often spotted with brown at the margin. It attains considerable dimensions. It 

 varies much ; Peron constituted seven spurious species out of its varieties. A good figure 

 after an original drawing by Milne Edwards, may be found in the commemorative edition of 

 Cuvier's Regne Animal. 



Genus Rhizostoma, Cuvier. 



5. The Rhhostoma pulmo {R. Aldrovandi and Cuvieri of Peron) is one of the largest 

 of European Medusae, its disk growing to two feet, or even more, across. The umbrella is 

 hemispherical, thick, and of a bluish hue, scalloped at the margin. Beneath is a thick peduncle, 

 dividing into eight, long, tapering arms. At their bases are great, fringed, ovarian lobes, 

 tinted with yeUow and purple. It is usually stated to be plentiful on the English shores, but 

 I have seldom met with it. 



Genus Cassiopea, Peron. 



6. The Medusa lunulata of Pennant, Urtica marina oetopedalis of Borlase, is a species 

 of Cassiopea. It is the Cassiopea Borlasea of Peron, and C. rhi%ostomoidea of Tilesius. 

 The disk is large^ wide, depressed, and campanulate ; the margin scalloped, but not ten- 

 taculated. There are eight ovaries below, opening by as many orifices, and eight pinnated 

 arms with furbelowed appendages at their bases. A good figure of this species is given by 

 Tilesius, in the Act. Acad. Nat. Cur. vol. xv, pi. 71. It is named on the plate C. anglica. 



Genus CYANiEA, Peron. 



7. Next to the Aurelia aurita, the commonest Medusa of our seas, is the large Cyancea 

 capillata, formidable on account of its stinging power. The disk is wide, and nearly flat, of 

 a pale yellow or tawny colour, deeply scalloped at the margin into sixteen quadrate lobes, 

 between each pair of which, in a deep notch, is a conspicuous pedunculated ocellus. Eight 

 brownish rays proceed towards these ocelli, from a circle of reticulated, quadrate, brown mark- 

 ings, giving the whole disk a beautifully stellate appearance, depending on the arrangement 



