120 



CRUSTACEA. 



This rare species is distinguished from the common Z. nodosa 

 and Z. bispinosa by its more uniform convexity and by the orbi- 

 cular form produced by the length so nearly equaling the width, 

 as well as the single, angular, pointed spine on each side. The 

 different projections on the posterior half of the carapace are 

 much less strongly marked than in the other species, though 

 having the same form and position. 



Rare in the London clay of Sheppey. 



(Col. University of Cambridge.) 



Of this genus {Zanthopsis) authors describe from the London 

 clay at Sheppey the Cancer Leachii (Desm.), which from the im- 

 perfection of the specimen described originally (even the mar- 

 gins of the carapace being absent), I do not think it is possible 

 to recognise with any certainty. Also belonging to it and from 

 the same locality is the Brachyurites hispidiformis of Schlotheim 

 (Nachtr. z. Petrefactenk. t. 1. f. 3), which for a wonder has 

 escaped insertion in my friend Mr. Morris's elaborate ^ Cata- 

 logue '; it has the exact form and strong nodulation of the Z. no- 

 dosa, but having the two posterior pair of spines even more pro- 

 duced and slender than in the Z. bispinosa. 



Podopilumnus (M^Coy), n. g. 



Gen. Char. Carapace having the front and antero-lateral margins 

 forming a semielliptical 

 curve, antero-lateral mar- 

 gins not compressed, tu- 

 mid, obtusely rounded, 

 with about three small spi- 

 nose tubercles ; front nar- 

 row, slightly projecting, 

 deeply four-lobed (inclu- 

 ding the inner angles of 

 the orbits), with a shal- 

 low furrow extending a 

 short way on the back 

 from the middle notch ; 

 orbits large, oval, lower 

 margins denticulated, a 

 small fissure ill the under 

 margin at the outer angle Diagram of the genus Podopilumnus. 

 (and a doubtful trace of «• Carapace, thighs and chelae ; h, abdo- 

 one in the upper margin) ; '"^" .^^ female the two last dotted joints 

 , V 1 ° i put in from their impressions on the 

 posterior lateral margm breast-piece; c, profile of carapace 

 straight, longer than the showing the abrupt downward curve of 

 anterior, converging to- the front, 

 wards the truncated base ; posterior half of the carapace flat- 



