AMPHIPODA. 



CRUSTACEA. 333 



segments on each side terminating in a long, curved spine. I 

 have found it, rather abundantly, in fishes. 



Genus MYSIS, Latr. 



M. spiNULo'sus. Tail terminated by two short spines and tico 

 longer, ciliated plates folding inwards. 



Cancer pedatus, Fabr. ; Fauna Grant. 243. 



Mjsis saltatorius, Lam. ; .4re. sans Vert., v. 346. 



Mj'sis spinulosus, Desm. ; Consid., 242. 



Mysis Fabricii, Leach ; Griffith's Cuv., xiii. (Crust.) pi. 17, f. 4. 



Mysis Leachii, Thompson ; Zool. Researches, i. 27. 



This curious little animal may be found abundantly, in the midst 

 of winter, in still water along the margins of bays. Its head seems 

 to have a long pair of beautifully fringed shears attached in front ; 

 each joint is marked upon the back with a black star ; and be- 

 tween the legs of the females is seen a large sac, containing eggs. 

 Two of the antennse are very long ; and the whole is quite trans- 

 parent. It is about an inch in length. , 



Genus NEBALL\, Leach. 



A single species has been observed, but the species has not 

 been satisfactorily made out. It is small, the body covered by a 

 single piece like a cuirass, the tail suddenly narrowing, long, and 

 terminating in two bristles. Multitudes are sometimes found in 

 the stomach of a sinde fish. 



b' 



\ i<- " 



AMPHIPODA. 



The Amph'ipoda are small Crustacea, inhabiting both fresh and 

 salt water, and some of them are well known to every one who is 

 familiar with the sea-shore, under the name of Sand-fleas, Beach- 

 fleas, &c. They are capable of swimming and leaping, but not y, 

 of walking. Their feet are sliort and unequal, and their body is _ / 

 usually so arched as to render it impossible to maintain themselves 





