GENUS THYSANOPODA. 



345 



Paris Museum. The remarkable peculiarity in the re- 

 spiratory apparatus distinguishes it at once from every 

 other form of Crustacea, and notably from its congeners in 

 the same family ; and the situation of the ova, which I am 

 enabled to supply from the new species about to be de- 

 scribed, is not less remarkable. 



