Gammarus, 
Fabricius, 
74 Proceedings of the Royal Physical Society. 
way toward the preparation of a more complete and com- 
prehensive catalogue of the Crustacean fauna of the district, 
they will have served a useful purpose. 
In the present paper I can only overtake the Amphipoda 
and Isopoda, and leave the Copepoda, Ostracoda, and 
Cladocera, for future papers. 
AMPHIPODA. 
GAMMARID4. 
Gammarus pulex (Pennant). 
1776. Cancer pulex, Pennant, Brit. Zool., vol. iv., p. 17. 
1825. Gammarus pulex, Desmarest, Consid. sur les Crust., p. 266, 
t. 45, HS: O: 
1840. e fluviatilis, M. Edwards, Hist. Nat. des Crust., 
p. 45, t,o. 
1863. - pulex, Bate and Westwood, Brit. Sess.-eyed Crust., 
vol. i., p. 388. 
Habitat.—Common in streams and lakes, not only within 
our district, but throughout these islands, and appearing to 
prefer localities where the water is clear and pure. So far 
as I know, this is the only fresh-water Amphipod in Scot- 
land. In England, species belonging to other two genera— 
Niphargus (Schiodte) and Crangonyx (Sp. Bate)—are recorded 
from various localities, where they are sometimes spoken of 
as well-shrimps, because of their being most frequently 
observed in old pump- or draw-wells, such as are still to be 
seen in the vicinity of country villages. I have carefully 
examined a number of such wells in outlying districts round 
Edinburgh, but have failed as yet to find any trace of these 
Crustaceans. There is little, if any, definite information 
regarding the fossil distribution of G. pulexin Scotland. Last 
year, in a paper read to this Society, I recorded the occur- 
rence of a Gammarus in a lacustrine post-Tertiary deposit 
at Kirkland, Leven, Fifeshire, which I referred doubtfully 
to G. pulex, as the specimen was incomplete. This is the 
only Scotch record that I know of. 
