OF WESTEEN SIND. 265 



The anterior bourrelets are somewhat tumid, as are the lateral, and the posterior is flat 

 and the largest. The periproct is broader than the peristome, is close to the margin, 

 and is elliptical with sharpish sides, and the anterior margin is more curved than 

 the posterior. 



The ornamentation of the interporiferous areas, abactinally, is very distinct, not 

 crowded, and consists of sunken tubercles and intermediate granulated structure. It is 

 slightly smaller than the ornamentation on the interradia, which is rather more distant. 

 It becomes coarse and crowded at the margin from the narrow and projecting inter- 

 mediate tissue, but it increases in size, distinctness, size of intermediate tissue, and 

 . granulation towards the peristome. It becomes small again on the inner slopes of the 

 bourrelets. Small behind the periproct, it is larger anteriorly to it. 



Dimensions. Length 115 millim., breadth 106 millim., height 40 millim. 



Belative dimensions. Length 1, to breadth 0-92, to height 0-35. 



Locality. Nari series (Oligocene). Pokhran, 50 miles S.S.W. of Sehwan. Survey- 

 number G -g-j-. 



Illustrations of the Species in Plate XLII. 



Fig. 1. The test, abactinal view. 



2. Actinal view. 



3. Lower longitudinal section. 



A second specimen is flatter, and has the posterior interporiferous areas narrower 

 than the type just noticed, otherwise they are identical. Length 105 millim., breadth 

 99 millim., height 35 millim. The relative dimensions are: — length 1, to breadth 

 0-94, to height 0-33. 



9. EcHiNOLAMPAS TUMiDA, Duncan & Sladen. Plate XLIII, Figs. 1-5. 



The test- is very large, slightly longer than broad, not quite circular in marginal 

 outline. It is about half as high as broad, very tumid at the margins, and swollen 

 actinally ; the peristome, which is rather excentric in front, being in a shallow broad 

 depression. The highest' point of the test is in front of the centre, and is at the apical 

 disk ; and the test slopes suddenly and boldly from that spot to the tumid anterior 

 margin, and much more gradually backwards to the sharper margin over the periproct. 

 The whole of the front of the test presents a very convex and massive appearance. But 

 the upper part of the test is not rounded off equally with the flanks, and is more or 

 less conical. - The posterior margin slopes upwards and backwards from the actinal 

 surface, so that the inframarginal periproct is seen slightly from behind. 



The apical system is small. The ambulacra are long, but do not extend close to 

 the margin ; broad, with rather narrow poriferous zones which are nearly equal in each 

 ambulacrum. There is a slight tendency to close in the antero-lateral ambulacra, and 

 the poriferous zones of the postero-lateral are a little closer together at their extreme 

 ends than midway ; but the anterior ambulacrum is widely open. All the interpo- 

 riferous areas are flush with the test and the poriferous zones also. 



The anterior ambulacrum is long, lanceolate, and shows no tendency to close ; its 



2n2 



