DAPHNIA. 
269 
Gen. 140. DAPHNIA, Milller . 
Head produced downwards into a more or less prominent 
beak. Upper antennse exceedingly small, one-jointed, and 
situated under the beak ; lower antennse large and powerful. 
The largest British species is not above -j- of an inch long. 
Daphnia pulex, Linn. sp. Branched Water-flea . (Plate 
XYI. fig. 1.) — Carapace oval, transparent, dorsal margin 
smooth; lower extremity of the valves ending in a sharp 
spine serrated on the edges. 
Hab. Pools and ditches of standing water. Common 
from April to January. 
Daphnia psittacea, Baird. — Carapace oval, transparent; 
head large, squarish, front part beaked like the beak of a 
parrot ; dorsal margin of the carapace serrated. 
Hab. Pond on Blackheath (Dr. Baird). 
Daphnia Sch,efeeri, Baird. — Carapace nearly circular, 
surface finely reticulated ; head small. The largest British 
species. 
Hab. Ponds, Bexley Heath, Kent; and ponds, Norwood 
Green, Surrey. 
Dr. Baird describes the motion of this species through 
the water as being peculiar ; it is a tumbling, heavy sort 
