28 HISTORY OF CRUSTACEA. CHAP. IV. 



hands of the first pair of feet. The two species in 

 which I am acquainted with this structure are amongst 

 the most salacious animals of their order, even females 

 which are laden with eggs in all stages of development, 

 not unfrequently have their males upon their backs. 

 The two species are nearly allied to Melita palmata 

 Leach (Gammarus Dugesii, Edw.), which is widely 

 distributed on the European coasts, and has been fre- 

 quently investigated ; unfortunately, however, I can 

 find no information as to whether the females of this or 

 any other European species possess a similar contriv- 

 ance. In M. exilii all the coxal lamellae are of the 

 ordinary formation. Nevertheless, be this as it will, 

 whether they exist in two or in twenty species, the 

 occurrence of these peculiar hook-like processes is 

 certainly very limited. 



Now our two species live sheltered beneath slightly 

 tilted stones in the neighbourhood of the shore : one of 

 them, Melita Messalina, so high that it is but rarely 

 covered by the water ; the other, Melita insatidbilis, a 

 little lower; both species live together in numerous 

 swarms. We cannot therefore suppose that the loving 

 couples are threatened with disturbance more frequently 

 than those of other species, nor would it be more difficult 

 for the male, than for those of other species, in case of 

 his losing his female, to find a new one. Nor is it any 

 more easy to see how the contrivance on the body of 

 the female for insuring the act of copulation could be 

 injurious to other species. But so long as it is not 

 demonstrated that our species are particularly in want 



