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HISTORY OF BRITISH CRUSTACEA. 
Gen. 11. PIBIMELA, Leach . 
Carapace nearly as long as broad. Outer jaw-feet with 
the third joint having the fourth inserted by its inner edge, 
and prolonged much beyond it over the epistome. Abdomen 
of the female of seven joints, of the male formed of five. 
Pirimela denticulata, Mont. sp. Toothed Pirimela . 
(Plate III. fig. 1.) — Carapace smooth, strongly bossed on 
the stomachal, genital, and branchial regions ; concave on 
the hepatic regions ; latero-anterior margins on each side, 
with four or five strong flattened teeth. Hands furnished 
with a slight crest above, and one or tw r o grooved lines on 
their outer face. 
Not a very abundant species. It is found on the south 
coast of England; Mr. Norman says it is apparently not 
uncommon among weeds at extreme low-water mark in 
Guernsey and Herm. It has been found also on the coasts 
of Scotland and Ireland. 
Pam. PORTUNIDjE, Leach. 
In these the last pair of feet are much flattened out side- 
wise, and the toe in particular is dilated into an oval, thin- 
edged plate, which, striking obliquely upon the water, acts 
