MK. T. EDWABD OK THE HABITS ETC. OE THE HTPERIID^. 143 



Stray Notes on some of the smaller Crustaceans. Note I. On the 

 ■ Habits &c. of the Sy^periidcB. By Thomas Edwaed, A.L.S. 



[Eead June 21, 1866.] 



It would appear, from works on this department of the animal 

 kingdom, that carcinologists are unanimously of opinion that the 

 Hyperiidse are parasitical in their habits. And in the most recent 

 monograph on the subject we are told that the species are found 

 to exist only in the gill-cavities of Medtisce, though they are also 

 occasionally found on fish, 



Trom this I in a great measure dissent. That some of the 

 species are at times found in Medusce I know. But is the 

 Medusa their true habitat? I believe rather that, instead of 

 being their natural abode, it is simply a place oeeasionally chosen 

 for convenience' sake, or to suit existing circumstances as it 

 were. But, since I have no wish to interfere with the ideas or 

 researches of others, I shall in my remarks confine myself more 

 particularly to what has come under my own observation. 



Before discussing the habits of the species, I would here say a 

 few words as to the sexes, so as to save time and useless repetition. 

 I consider the genus Lestrigonus of Milne-Edwards and subse- 

 quent writers to be nothing more nor less than the male of 

 Hyperia. I am led to this conclusion from the remarkable simi- 

 litude which exists among them, and from the fact that, in all the 

 species {five in number) which I have met with, the sexes have 

 always been associated, except in the case of Lestrigonus Kina- 

 Jiani. I have not, as yet, been able to detect a female for him, 

 but have no doubt whatever of the others. It may. here be men- 

 tioned that I speak only of those I have myself found. Eor my 

 own part I have little or no difficulty whatever in tracing, almost 

 from the ovary of the parent up to a state of maturity, Lestrigonus 

 exulans as the male of Hyperia galba. The differences between 

 the two are so slight as scarcely to be worth noticing, except 

 perhaps in a sexual point of view. Their external appearance is 

 almost the same, both in form and colour ; and in ha,bits they are 

 wholly alike. 



The same may be said of H. olivia and H. medusa/rum, the males 

 of which have not yet been described, but both of which I have 

 lately discovered, and which must, as a matter of course, be called 

 Lestrigonus, — and also another species, believed to be new, and 

 not yet named, and smaller than the last, which we shall here^ 

 but only for convenience' sake, as it is in the hands of another to 



