IV 



ON THE ANATOMY AND THE AFFINITIES OF THE 

 FAMILY OF THE MEDUSA 



Philosophical Ti-ansactions of the Royal Society, 1849, P^- ^i /• 4i3- 



1. Perhaps no class of animals has been so much investigated 

 with so little satisfactory and comprehensive result as the family of 

 the Medusce, under which name I include here the Medusa, Mono- 

 stomatce, and RkizostomidcB ; and this, not for the want of patience or 

 ability on the part of the observers (the names of Ehrenberg, Milne- 

 Edwards, and De Blainville are sufficient guarantees for the excellence 

 of their observations), but rather because they have contented them- 

 selves with stating matters of detail concerning particular genera and 

 species, instead of giving broad and general views of the whole class, 

 considered as organized upon a given type, and inquiring into its 

 relations with other families. 



2. It is my intention to endeavour to supply this want in the 

 present paper — with what success the reader must judge. I am fully 

 aware of the difficulty of the task, and of my own incompetency to 

 treat it as might be wished ; but, on the other hand, I may perhaps 

 plead that in the course of a cruise of some months along the east 

 coast of Australia and in Bass's Strait I have enjoyed peculiar oppor- 

 tunities for investigations of this kind, and that the study of other 

 families hitherto but imperfectly known, has done much towards sug- 

 gesting a clue in unravelling many complexities, at first sight not ver)- 

 intelligible. 



3. From the time of Peron and Lesueur downwards, much has 

 been said of the difficulties attending the examination of the Medusa;. 

 I confess I think that they have been greatly exaggerated ; at least 

 with a good microscope and a good light (with the ship tolerably 



