178 Prof. F. M'Coy on the Classification of 



the great one, but about one-third less wide ; other legs very 

 slender (third and fourth pair about 3 lines wide), subcom- 

 pressed, smooth. 



This fine species much resembles our common recent lobster 

 at first sight, and has as large or even more robust claws, but 

 similarly armed : in by far the greater number of specimens the 

 characteristic prolongation of the cheeks, with its spinose keel 

 becoming fixed in the matrix, causes the entire front of the cara- 

 pace from a little behind the rostrum to be broken off, and so 

 leaving no trace of this part of the carapace, heightens the resem- 

 blance indicated by the specific name. 



Common in the London clay of Sheppey. 



(Col. University of Cambridge and Mr. Bowerbank.) 



Hoploparia Belli (M'Coy). 



Sp. Char. Carapace averaging from the orbit to the posterior 

 side margin 1£ inch, depth of side 9 lines, closely punctured 

 on the middle of the back, and very closely and uniformly gra- 

 nulated over the sides ; nuchal furrow considerably nearer the 

 posterior margin of the carapace than the edge of the orbit 

 (measured a little one side of the mesial line), its ends reach 

 two-thirds of the way from the mesial line to the lateral mar- 

 gin ; X-like cheek-furrow strong ; sheath-like prolongation of 

 the cheeks obtusely rounded, the margins and lateral angles 

 much inflexed, about half the length of the rostrum, two or 

 three obtuse, undefined nodulations on the rounded promi- 

 nence which extends backwards from its contracted carinate 

 end towards the cheek- furrow ; bayonet-shaped antennary scale 

 narrow, extending as far as the tip of the rostrum ; one blunt 

 tubercle about twice its diameter from the median line on each 

 side of the base of the rostrum, and another similar one at an 

 equal distance below it on each side : abdomen thick, each seg- 

 ment having a gently convex smooth anterior articular portion 

 divided by a strong deep furrow from the rest, which is flat- 

 tened and very closely and strongly punctured ; epimeral ex- 

 tremities of the first joint rudimentary, of the second broad, 

 subquadrate, rounded on the anterior and external edges, sub- 

 truncate behind, with the angle forming a short spine, third, 

 fourth, fifth and sixth terminating in broad triangular plates, 

 slightly falcate, the sixth rather longer than the preceding 

 ones, and having the posterior lateral angles produced back- 

 wards into a small spine on each side of the base of the seventh 

 joint or middle tail-flap, which latter is subquadrate, its length 

 and the width of the base being equal, narrowing towards the 

 end, which is rounded and terminates at each angle in a small 

 sharp spine ; side margins thickened, minutely dentated : first 



