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Having now enumerated and described those naked-eyed Medusae, which have come 

 under my notice* in the British seas, I shall proceed to offer a few remarks on their systematic 

 relations with other animals of their class, and on the affinities of the Pulmograde Acalephse, 

 with the members of other sections of Radiata. But before I do so, I think it best for the 

 convenience of my readers to enumerate very briefly the higher or Steganopthalmatous 

 Pulmograda, known to me as inhabiting our coasts, in the hope of directing attention to the 

 study of the larger species, which afford fine materials for original research. I look forward 

 at some future time to describe and figure them in a companion Monograph to this, but require 

 many more observations and drawings before that can be done in a satisfactory manner. 



Being so much larger than the subjects of this volume, they are much more familiar to 

 frequenters of the sea-side ; and as several of the species are gregarious and very generally 

 distributed, they present good opportunities for the acquirement of a knowledge of the 

 structure of Medusae in general. Every person who has been in a boat on a calm day, or 

 looked over the side of one of our harbours when the tide was flowing in summer, must 

 have seen large transparent gelatinous disks, with fringed margins, contracting and expand- 

 ing, making their way beneath the surface of the water. All who have walked much 

 along the wet sands when the tide is out, must have met with great pads of transparent jelly, 

 marked in the centre with purple circles, or edged and rayed with brown. The latter, when 

 handled, sting severely ; the former are harmless. They are the two most common kinds of 

 covered-eyed Medusae, members of the genera Aurelia and Cyancea. The following brief 

 notices will enable the reader to distinguish between our native species of Pulmograda 

 Gymnopthalmata. 



Genus Aurelia, Peron. Medusa, Eschscholtz. 



1 . To this genus belongs the commonest of our native species, the Aurelia aurita, a 

 hemispherical, translucent, bluish, gelatinous disk, margined with a close fringe of fine 

 filiform tentacula, interspersed at eight points by as many ocelli, each composed of an egg- 

 shaped, pedunculated, black body, with a red speck above it. The sub-umbrella is marked 

 by numerous radiating vessels, dichotomously dividing and most of them anastomosing in their 

 course towards the margin. Sometimes these vessels present a deep purple hue, and then 

 we have the spurious species Aurelia lineolata of Peron, A. radiolata of Lamarck, and 

 Medusa purpurata of Pennant. Borlase first noticed this variety, and correctly considered it 

 such, and not distinct from the ordinary form. Four long arms, with membranous and 

 fringed edges, spring from the centre of the sub-umbrella. In the middle of them is the 

 mouth. In particular states of the animal, the fringes and margins of the arms serve as 

 marsupia for the eggs. Between each pair of arms is a raised cartilaginous tubercle, with an 



* Notices of doubtful or imperfectly described forms, will be found in the Bibliographical 

 Appendix. 



