DECAPOD CRUSTACEANS OP THE OXFORD CLAY. 549 



are not uniform, but gradually increase in size as they approach the 

 outer border, where they become more prominent, especially on the 

 proximal portion ; the tubercles are conical at the base, flat-topped, 

 with a central mamilla on the summit. 



On several small specimens of the dactylopodite the tubercles are 

 more uniform in size and are less crowded. Etallon figures the 

 denticles on the proximal portions of the dentary border of the 

 fixed finger as being considerably longer than the rest, and Oppel 

 states that this character occurs on the dactylopodite; but the 

 St. Ives specimens do not exhibit this feature on either finger. 



Width of distal end of hand 1| inch; length of dactylopodite 

 2| inches. 



Oxford Clay, St. Ives. 



Coll. Mr. George, Xorthampton. 



Specimens examined 4. 



Mr. Etheridge mentions (Phillips's Manual, part 2, p. 475) that 

 Eryma Babeaui occurs in the Kimmeridge clay. 



Eeyma Georgii, nov. sp. (PI. XVI. fig. 4.) 



Carapace nearly twice as long as high ; all the sulci large and so 

 deep as to render the several lobes ventrose ; the dorsal surface of 

 all the regions bears rather large, conical, but not very prominent 

 tubercles, which are uniform in size and regularly disposed, about 

 one and a half diameter apart, and four or five in a quarter of an 

 inch. (Frontal region imperfect.) Chelae of first pair of limbs 

 robust ; the length of the hand is rather greater than the width of 

 its distal end, and rather more than half the total length of the 

 carapace ; it bears regular tubercles which are rather smaller and 

 more crowded than those on the carapace. The fingers are subequal 

 in size, rather longer (?) than the hand, both slightly curved in the 

 same direction, nearly smooth and punctated ; outer border rounded ; 

 dentary margin with a series of small, depressed, dentary tubercles. 

 Carpopodite two fifths of the length of the hand, and with a few 

 tubercles ; distal end of the meropodite with a stout spine. A chela 

 of the second (or third ?) pair, of small size, has straight, slender 

 fingers, which are nearly as long as the hand, and both are impressed 

 by several setigerous puucta. 



Length of carapace from frontal to posterior border 1|- inch ; 

 height of carapace nearly 1 inch. 



Oxford Clay, St. Ives. 



Coll. Mr. George, Northampton. 



Specimens examined 3. 



I have not been able to identify this form with any described 

 species. 



The deep regional sulci and the large size of the tubercles on the 

 dorsal surface of the carapace distinguish it from its allies E. ventrosa, 

 E. ijrophiriua, E. numismalis, and E. elerjans It nearly resembles 

 E. Grepioini, 0pp., from which, however, it difi'ers in the conforma- 

 tion of the anterior portion of the carapace and the larger size of 

 the surface-tubercles. The chelae of this species bear no resem- 



Q.J.G.S. No.168. 2p 



