142 HISTORY OF BRITISH CRUSTACEA. 



with them ; in the male this appendage is very small, but in 

 the female it is greatly developed, and the two form a pouch 

 in which the eggs are deposited and the young are hatched, 

 hence they have been named Opossum Shrimps, from this 

 pouch somewhat resembling in use the pouch of the Mar- 

 supial animals. 



These Opossum Shrimps are frequently met with in 

 countless myriads towards the surface of the Greenland 

 Sea. They seldom approach the shore or retire to the 

 lower part of the ocean. Otho Fabricius, in his ' Fauna 

 Groenlandica/* which is a model for a work of that na- 

 ture, has described three species; two of these (Mysis pe- 

 datus and M. oculahis) called Illcerak and Irsitngalc by the 

 Greenlanders, small though they be, form the chief part of 

 the food of the common Whale {Balana mysticetus). As 

 he remarks (p. 33), it is, at the first thought, truly wonder- 

 ful that so large an animal should be supported and acquire 

 so much fat from so slender and trifling a subject ; but 

 when one reflects on the abundance of them being so great 

 that the Whale, when it opens its mouth, must draw in 

 many thousands at a gulp, the wonder is diminished. The 

 little shrimps seem to play about the fringes of the " whale- 



P. 245. 



