AMPH1PODA. 159 



few instances there are four eyes, and in one genus only a 

 single pair of antennae ; the mandibles are furnished with a 

 palpus. There are branchial vesicles under the thorax ; 

 the first five pairs of abdominal limbs differ in form, and 

 are used in locomotion. The females carry their eggs 

 beneath the thorax, frequently in flabelliform appendages 

 fixed to the base of their legs. 



The species are all small ; Professor Edwards knew not 

 any that was longer than eighteen lines, but they make up 

 in numbers for any deficiency in size. They are found in 

 every sea. Some of them abound in the Arctic regions, 

 and as an instance of their voracity and abundance, Dr. 

 Sutherland* mentions that in Davis's Straits he has seen an 

 entire seal reduced to a perfect skeleton in less than two 

 days by the attacks of the Gammarus areticus ; he adds, 

 " I observed a dead seal in the water, which an Esquimaux 

 had been towing for three hours. A great number of these 

 active little creatures were in the water around it, and they 

 could be seen going in the direction of one of the wounds 

 in the skin, by which they entered a large chamber which 

 they had hollowed out beneath in the flesh and blubber, of 

 which they are very fond." The arrangement of Amphi- 



* Voyage in Baffin's Bay and Barrow's Straits, i. 142. 



