SPHHMROMA SERRATUM. 407 
formed into a distinct species, Sph. trigonum, by Risso 
(Crust. de Nice, p. 14'7). 
When alive, the body is ashy coloured or whitish, 
varied with reddish and dark grey; the eyes black; the 
antennz fulvous; the legs ashy, with fulvous claws tipped 
with black. 
Young individuals, measuring not more than two lines 
in length, have the outer edges of the side appendages of 
the tail (uropoda) entire, and not serrated. 
This species lives in numerous societies under stones 
and amongst the pebbles and gravel of the coast; and is 
found on the English and French coasts of the English 
Channel, from Kent to Cornwall, and in the Medi- 
terranean. We have dredged fine specimens in Plymouth 
Sound in the month of August. Dr. Kinahan obtained 
it in the River Lagan, Belfast, and in the River Dodder, 
Dublin. We have observed quantities in the brackish 
streams on Loughor Marsh, near Swansea, mixed with 
Palemon, Carcinus, and Talitrus. 
