78 CYANEA. 
of the organs on the sub-umbrella, which is furnished with long, plicated, and furbelowed 
membranous arms, and fasciculi of extremely extensile, stinging, filamentary tentacles. The 
varieties of this Cyanea have been made into numerous spurious species by Peron. 
8. Cyanca Lamarckii, Peron. Not quite so common as the last, though very frequent 
in the Irish sea. It is easily distinguished by its more convex disk, of a deep ferruginous hue 
in the centre, and divided at the margin into eight four-lobed triangular lobes, the eye notches 
at their apices. The ovaries are of a rose colour. It stings equally severely with C. capillata. 
Better figures of both these Medusa are wanted. For one of the former, the memoir of 
Gaede, in the ‘Bonn Transactions,’ may be consulted; the latter is represented in the 
92d plate of the ‘ Encyclopédie Méthodique, Vers’ (copied from Dicquemare). 

All the genera and species of higher Pulmograda are distinguished from the lower forms, 
to the description of which this treatise is devoted, by a much greater complexity of structure, 
especially in the vascular system and organs of sense, and also in the arrangements of the 
reproductive system. The vessels branch and anastomose; the ocelli are protected by 
complicated coverings, and are themselves of more perfect organization ; the generative glands 
are more highly developed in the Steganopthalmata than in the Gymnopthalmata. We have 
no instance of the Medusa or perfect state of the former propagating itself by gemmation, 
whilst such a mode of procreation occurs in several cases, as we have seen, among the 
latter. Taking one character with another, then, we cannot doubt that the Pulmograda 
Steganopthalmata are higher in the series than the Pulmograda Gymnopthalmata. This is 
borne out by an examination of the phases of development and metamorphosis of the larva in 
the latter. The observations of Sars, Dalyell, Reid, and Steenstrup indicate that the early 
stages of the durelig and Cyanee, correspond closely structurally with the perfect condition 
of the naked-eyed Pulmogrades. 
Hitherto the genera of these two very distinct, yet proximate, tribes have been grouped 
together, without much respect to their natural affinities or serial order. Among the more 
important attempts at arrangement of the Acalephe, are the systems of Peron and Lesueur, 
of Lamarck, Eschscholtz, Cuvier, Blainville, Brandt, and Lesson. In the first of these, all 
the Pulmograda are grouped under two tribes, termed agastrie and gastric, the latter being 
subdivided into monostomous and polystomous. Such a division is founded on a complete 
misapprehension—one which prevailed generally among zoologists, until Milne Edwards 
carefully examined the anatomy of Carybdea marsupialis, which, however, in the arrange- 
ment under consideration, was placed in the gastric division, owing to the- naturalists who 
proposed it having mistaken the whole concavity of the sub-umbrella for a stomach! Geryonia 
was, on the contrary, enumerated among agastric genera, the nature of the true stomach, 
situated at the extremity of the peduncle in that group not having been recognised. We 
find Oceania, which included a heterogeneous assemblage of naked-eyed species, placed side 
by side with Pelagia, in a division of the Monostomous Gastric Medusee. The greater number 
