POLYPHEMUS. 
275 
William Wing, an admirable draughtsman of Insects and 
Crustacea, and an assiduous student of Natural History in 
general.^ 
Fam. II. POLYP HEMIDJE. 
Four pairs of feet, not included in the carapace. Eye 
very large. Lower antennae two-branched, one branch with 
four joints, the other with three. Lower part of carapace 
having a large empty space for the ova and young. 
Gen. 146. POLYPHEMUS, Muller . 
Head distinct from the body. Abdomen long, projecting 
externally from the shell. The eye is so large in the adult 
that it seems to occupy the whole head. 
Polyphemus pediculus, Linn., sp. (Plate XVI. fig. 2.) 
—Body oval, separated from the head by a deep notch. 
Hab. Ditch near Richmond, opposite Isleworth. Dr. 
Baird observes that it always swims on its back, and gene- 
rally horizontally, with quick repeated motions of the an- 
tennae and legs, which carry it rapidly through the water. 
* The genus Diaphanosoma of S. Eischer is synonymous with the above, 
and perhaps the species (D. Brandtii). 
