266 BRITISH ENTOMOSTRAflA. 



the females are the most abundant. Their habits arc 

 rather difficult to observe, as they generally die soon after 

 the fish upon which they live are taken out of the water. 



Pickering and Dana introduced several individuals into 

 a glass of salt water, soon after the fish was caught, and 

 remarked that the greater portion of them sought the 

 surface, where they attached themselves to the sides of 

 the glass. Many quitted the water entirely, and crept 

 up the glass for an inch or two above the surface. In 

 doing so, they carry a portion of water with them, confined 

 under their broad carapace, the margin of which is closely 

 attached to the side of the vessel, and thus are enabled 

 to exist for some little time. They did not seem, however, 

 to make any attempt to return to the element they had 

 left, and died soon afterwards. 



\Vhen living attached to the fish, should they be 

 touched or disturbed, they move with considerable ra- 

 pidity, and travel over the body of their host, moving 

 along with equal facility either backwards or forwards. 

 By means of their natatory or branchial feet, they swim 

 also with considerable rapidity, and no doubt occasionally 

 change from one fish to another, as Strom had long ago 

 observed. Their food does not seem to be exactly ascer- 

 tained. Strom asserts that they live by sucking the blood 

 from the fish, and says that he has seen that fluid flow 

 into the mouth of the Caligus, and thence through the 

 neck and whole body. 



As Miiller justly remarks, however, with regard to 

 Strom's observations, they carry little weight with them, 

 for as he mistook the tail for the head, he must have 

 misunderstood the nature of what lie saw, and perhaps 

 taken the genital organs for the mouth. "I cannot 

 believe," he says, "that they suck the fishes, but it is 

 more probable, from their moving their branchial feet, as 

 all the rest of the Entomostraca, that they cause the water 

 In carry to their mouth the molecules floating in it, and 

 the mucus from the fish." O. Fabricius also says, that 

 (lie >peries lie describes nouiT>he> itself \\illl the mucous 



