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



(large) hand with six or seven conical tubercles, that of the 

 left with about four, outer side of each hand with two very 

 obscure small tubercles near the carpus, and one much larger 

 but less distinct near the origin of the fingers ; two blunt teeth 

 on the inner edge of each finger ; tail of the female broad 

 ovate, of the male narrow hastate, terminal joint triangular, 

 about ^-th wider than long, penultimate joint the same length 

 but a little wider, third joint much wider than the others, but 

 shorter than the fourth or fifth. Length about 1 inch 9 lines, 

 width 2 inches. 



Common in the London clay of Sheppey. 



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



Zanthopsis bispinosa (M'Coy). 

 Sp. Char. Carapace transversely oval, about one-fifth wider than 

 long, gently convex, two posterior pair of tubercles of the an- 

 terolateral margin forming short, flattened, sharp spines, the 

 anterior one forming a small, very obtusely angular projection ; 

 crest of the large hand with four or five tubercles, outer side 

 with two strong elongate tubercles near the carpus, and one 

 large obtuse one near the origin of the fingers ; tail of the 

 female broad oval, the last and the penultimate joint of equal 

 length, the latter twice as wide as long, fifth joint half the 

 length of the penultimate. 



This is considerably wider and flatter than the Z. nodosa, and 

 the tubercles on the branchial regions and those formed by the 

 genital, cardiac and intestinal regions are much less prominent ; 

 the hollow space along each side of the ridge formed by the medial 

 regions is punctured almost as strongly as the rest of the carapace ; 

 the tubercles on the ridge of the hand are fewer, but those on the 

 outer side much more strongly marked; it is moreover easily 

 distinguished by the two hind pair of tubercles of the antero- 

 lateral margins forming depressed sharp spines in the one and 

 large obtusely rounded nodules in the other. Length of carapace 

 1 inch 9 lines, width 2 inches 3 lines. 



Common in the London clay of Sheppey. 



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



Zanthopsis unispinosa (M'Coy). 



Sp. Char. Carapace suborbicular, length and width nearly equal, 

 evenly gibbous, sloping almost equally to the front and to the 

 back; tubercles of the branchial and medial regions nearly 

 obsolete, flattened, obscurely defined; anterolateral margin 

 with the posterior tubercle on each side forming a strong, 

 short, depressed triangular spine, the two anterior pair almost 

 obsolete, each indicated by a faint wave in the margin. Length 

 of carapace 1 inch 6 lines, width 1 inch 8 lines. 



