130 



CRUSTACEA. 



of the second pair ; carpus about one-third the length of the 

 arm and half the length of the hand, the width of which latter 

 at top exceeds half its length; three next pair of legs compressed, 

 gradually diminishing in size ; fifth pair not seen. At about 

 2 inches from their bases the external antennse are one-fourth 

 of an inch in diameter. 



I have great pleasure in dedicating this fine species to Mr. 

 Bowerbank, who has done so much to illustrate the fossil botany 

 and zoology of the London clay — his work on the former having 

 almost created the subject ; while the extraordinary extent and 

 beauty of the collections which he has made of the other fossils 

 of that formation are, I believe, quite unrivalled, and when fully 

 published will demonstrate a richness in the fauna and flora of 

 the eocene period in Britain for which few geologists are pre- 

 pared. I have especially to record my obligations to him for 

 sending me a large number of his choicest specimens of London- 

 clay Crustacea of those species which I informed him I was about 

 describing from the Cambridge collection, but the specimens of 

 which at my disposal did not fully exhibit all the characters of 

 the species ; and having mentioned my anxiety to render my de- 

 scriptions of those as perfect as possible, without entering further 

 on the extensive subject of the Crustacea of that formation. 



The present species is usually found with the abdomen doubled 

 close under the thorax, which latter is almost always crushed, 

 owing to the fragile delicacy of the crust. 



Rare in the London clay of Sheppey. 



(CoL University of Cambridge and Mr. Bowerbank.) 



Hoploparia (M'Coy), n. g. 



Etym. oirXa, arma, and Trapeia, gena. 



Gen. Char, Carapace minutely granulose, oblong, tumid, slightly 



Hoploparia. 

 compressed, a little deeper than wide, ending in front in a 

 strong sharp rostrum, the sides of which are strongly carinate 



