DAPHNlADyE. 
267 
Order CLAEOCERA * 
Body, except head, which projects, quite enclosed in two 
shells, joined on the back. Feet four to six pairs; joints 
partly cylindrical, and partly foliaceous and branchiform. 
Eye single, and very large. Two pairs of antennae ; the 
lower branched, large, and used in swimming. Mandibles 
without palpi. 
Fam. EAR Em ADM, Bair A 
Upper antennae generally very small ; lower large, gene- 
rally two-branched. Five or six pairs of feet, enclosed 
within the shell. Intestine straight. 
Feet in constant motion, and giving an undulatory motion 
to the water, and establishing a current towards the mouth. 
Dr. Baird informs us that the various species of this 
family are only to be met with in fresh- water, generally in 
ponds and ditches, some preferring those in which there is 
much duckweed (Lemuel) floating on the surface ; others 
delighting in horseponds where cattle come to drink. They 
are often found in myriads ; and as some of the species 
* KAaSos, a branch, and Kepas, a horn ; from their branched antennae. 
