260 THE FOSSIL ECHINOIDEA 



comparatively level surface behind the apex and then a sharper descent towards the 

 nipped-in projection over the periproct. 



The apical system is very excentric in front. The anterior ambulacrum is short 

 and narrower than the others, and is open distally. The antero-lateral ambulacra, 

 very nearly transverse, are not very long, have a tendency to close, for the longer 

 posterior poriferous zone curves towards the other, but still the ends are widely apart. 

 The posterior zones do not reach more than three fourths of the distance to the 

 margin, are open at the end, < and the poriferous zones are equal. The posterior 

 ambulacra are the longest and broadest. 



All the poriferous zones are well developed, very slightly sunken, are rather more 

 than one half of the breadth of the interporiferous areas, and have large outer comma- 

 shaped pores and smaller inner ones which are circular in outline. On the lateral 

 ambulacra there is much obliquity of the pairs of pores. The costse are well developed, 

 and have the usual row of miliaries on them. 



Actinally the more angular posterior part of the test contrasts with the rounded 

 anterior margin ; the greatest breadth is seen to be at a bulge anterior to the postero- 

 lateral ambulacra. The test is flattened above and behind the periproct, which is large, 

 inframarginal, curved in front, straight behind. 



The actinal surface is depressed around the central peristome. The ornamentation 

 is rather large, is nearly equal from the margin to the apex, but is much larger around 

 the peristome. 



Dimensions. Length 57 millim., breadth 51 millim., height 25 millim. ; distance 

 of apical disk from front 23 millim. Relative length to breadth 1 : 0'877 ; relative 

 length to height 1 : 0'43. 



Locality. Nari series. Neighbourhood of Laki. Survey -number G -^. 



Illustrations of the Species in Plate XL. 



Fig. 8. The abactinal view. 

 9. The side view. 



3. EcHiNOLAMPAS Radakensis, Buncau & Sladen. Plate XL, Fig. 10. 



The test is oval in outline, broadest on a line with the slightly excentric in front 

 apical system, longer than broad, broader than high, depressed, tumid at the anterior 

 and the lateral margins, and it rests on a surface between them and the excentric in 

 front peristome. The apical system is small, and the ends of the ambulacra there are 

 pointed and rather close. The anterior ambulacrum is rather tumid, is much the 

 shortest and much the narrowest ; it is open, but the poriferous zones tend to close, 

 the right being the longest ; the poriferous zones are narrow and the pairs of pores are 

 crowded. The interporiferous area is tumid. 



The antero-lateral ambulacra are petaloid and very wide apart ; both poriferous 

 zones are curved and narrow. The anterior is the shorter, and there is a tendency to 

 close. The interporiferous area is broad and tumid, and three times the width of the 



