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. 
