212 THE ZOOLOGIST. 
they do not go in head first, but stand on the one place, simply 
turning round and round, as if on a pivot, with their uropods 
lowered and cutting as they go. They no doubt assist very 
materially in the disintegration of the rocks, honeycombing them 
to such an extent that they are easily broken up by the waves .into 
sand, and so contribute to form the rocks of a future geological 
period. When these Isopods are captured they draw themselves 
up into a ball, and project their uropods, which are very strong 
and sharp. Fawn-colour along dorsal line, reddish brown at 
sides of somites. Port Jackson. 
Sub-order AMPHIPODA. 
Tribe GRAMMARIDES. 
45. Talorchestia quadrimana (Hasw.).—This is the common 
Sand-hopper, found in great numbers along the whole coast of 
New South Wales, wherever there are masses of decaying vege- 
table or animal matter. Length, 7 lines. 
