272 HISTORY OF BRITISH CRUSTACEA. 
Gen. 142. MACROTHBIX, Baird. 
Upper antennae flat and one-jointed, pendulous from the 
beak ; filament from end of first joint of front branch of 
lower antennae much longer than any of the others ; * eye 
accompanied with a black spot. 
Macrothrix laticornis, Jurine, sp. — Carapace oval, 
transparent, colourless, smooth. 
Hab. Ponds at Southall and Highgate, Middlesex ; Bel- 
fast. 
Near this, and probably only a rosy-coloured variety of it, 
is a species which has been named M. roseus. It has been 
found abundantly in Lochmaben Loch, in Dumfriesshire, 
where it forms great part of the food of the fish called the 
Vendace. Dr. Baird says it swims horizontally, and that 
the motions of its arms, as it bounds through the water, are 
soft and graceful. 
Gen. 143. BOSMINA, Baird. 
Upper antennae long, curved, cylindrical, consisting of 
* Hence the name Dr. Baird has given it, from p-aKpos, long, and 0pi£, a 
hair. 
