CYAMUS GRACILIS. 95 



first pair of legs of moderately large size, although smaller 

 than the following limbs. The species, according to 

 M. Roussel de Vauzeme, has the body small and oblong, 

 with a single branchia attached to each side of the third 

 and fourth segments, each branchia having two very short 

 appendages at its base, and the second pair of legs have 

 the large penultimate joint with a slight concave impres- 

 sion on their under surface. We regret that our igno- 

 rance of the precise locality of the supposed British 

 specimen above mentioned, and its immature condition, 

 as well as the very concise notice of this species by 

 M. Roussel himself, prevent us from giving a satisfactory 

 account of it. The only notice of its habits, as distinct 

 from those of C. ovalis, has been already detailed by us 

 in our account of the last-named species. 



