346 



STOMOPODA. 



MYSID/E. 



Thysanopoda Couchii. 



Specific Character. — Branchiae witli only one series of leaflets. Middle point 

 of the trifid apex of the central caudal lamina, not half the length of the lateral 

 ones. 



The general aspect of this curious species indicates at 

 once its near relation to Mysis, which the detail of its 

 organization confirms. The present species differs from 

 Th. tricuspida, the species on which Dr. Mihie Edwards 

 founded the genus, in several points, — the most striking 

 of which are the following. In Edwards's species the bran- 

 chioe, in addition to the primary leaflets ranged in a single 

 series along the stalk, have very numerous secondary fila- 

 ments attached to them — a circumstance vvliich I have not 



