3J1. A HISTORY OF RECENT CRUSTACEA 



AcaniMas vulgaris, whicti had been reduced to nothing but 

 skin and bones by these parasites. They hunt, he says, 

 in shoals, driving away the congers and other fish, but are 

 themselves devoured by the bream. (' Proceedings of the 

 Zoological Society, London,' for 1884, p. 44-). In this and 

 the preceding genus there is little difference between the 

 sexes, whereas in the next that difference is sometimes, 

 though not always, considerable. 



EurydicB contains nine species, but they are not all well 

 known. The actively swimming and viciously biting little 

 Eurydice pulchra, Leach, which should perhaps rather be 

 called Eurydice achatus (Slabber), is extremely common on 

 many of the sandy shores of Great Britain. There seems 

 a sort of conspiracy to deprive Slabber of the credit of his 

 observations, which for his period were by no means to be 

 despised. The specific name he chose no doubt refers to 

 the handsome markings, which, however, are rather stellate 

 or dendritic than agate-like, and which in this species are 

 retained even when the animal has been preserved for 

 many years in spirit. The eyes have a surface facetting. 

 Eurydice truncata, Norman, from St. Magnus Bay, Shet- 

 land, is described as having the ' superior antennae sud- 

 denly bent in a remarkable way at a right angle at the 

 junction of first and second joints of the peduncle.' 



Bathynomus has but a single species, but, in contrast 

 with the small stature prevailing in the species of Eurydice, 

 the West Indian Bathynomus giganteus, A. Milne-Edwards, 

 is by far the largest of all known Isopods. The eyes are 

 said to be placed wholly on the underside of the head, and 

 each to contain nearly 4,000 squared facets. There is a 

 tendency in other Cirolanidse for the eyes to adopt some- 

 thing of a ventral position, so that it is not on this account 

 necessary to place Bathynomus in a separate family. The 

 development of accessory branchi^ has been no doubt 

 necessitated by the animal's great size and its abyssal habi- 

 tat, to which the specific and generic names respectively 

 refer. Professor Milne-Edwards says that its pleopods 

 form ' a sort of opercular system, beneath which are found 

 the true organs of respiration, or branchi^. These re- 



