ECHINOIDEA. 25 



The omamentatioa of the upper surface consists of very small tubercles sunk 

 in shallow scrobicules, between which there are numerous minute granules. On 

 the lower surface the tubercles become much larger and the scrobicules are much 

 wider, with the exception of a narrow longitudinal band that runs from the post- 

 erior interambulacral bourrelet to the periproct. The lower surface is entirely 

 covered with the larger tubercles ; under a magnifying lens it will be seen that the 

 apparently smooth band is covered with minute granules surrounded by scrobi- 

 cules ; this feature, however, is only well seen on specimens which have not been 

 much worn by ■weathering. 



Locality and stratigraphical position. — Des Valley ; horizons Nos. 2 and 4, 

 Mazdr Drik, horizon No. 8. 



Bemarks. — 'Clypeolampas helios is so closely related to Clypeolampaa ovum 

 from the upper cretaceous strata of the Pyrenees that I first considered it 

 identical with that species, but on closer examination I noticed the following differ- 

 ences (provided, of course, that the figure of that species in the Pal6ontologie fran§aise 

 is correctly drawn): Clypeolampas ovum is broader on the anterior side and aceu- 

 minated behind, while just the opposite features are exhibited in Clypeolampas 

 helios, which is broader behind and contracted in front. The chief distinguishing 

 feature is, however, the higher and more conical shape of the test : the ratio -j- is 

 0'76 in Clypeolampas ovum, while it certainly does not exceed 0*68 in Clypeolampas 



helios. 



"Whether there really exists a longitudinal band on the lower surface covered 

 with minute tubercles or not I am unable to say. If it is really absent in Clypeolam- 

 pas ovum, it would form a good distinguishing feature from the Baluchistan 

 species. 



Oltpeolampas VISHNU, spec. nov. PI. IV. fig. 1-lc. 



Dimensions. 



Length L =46 mm. 



Breadth b =39 „ 



Height - h =14 „ 



i =-84 



L 



h .•• . . =30 



L 



Only a single specimen of this species has come under examination, and this 

 has suffered to such an extent from weathering that all the finer details are effaced. 

 The test is elliptical, a little narrower anteriorly than posteriorly ; the upper surface 

 is tumid and the apex is considerably excentral, being nearer the anterior margin ; 

 the profile forms, therefore, an unsymmetrical curve which slopes very gradually 

 toward the posterior, and steeply towards the anterior margin ; the sides are pretty 

 steep, slightly inflated, the ambitus rounded, the lower surface is flat, even a little 

 concave around the mouth. 



Apical disc not visible. 



Ambulaeral areas lanceolate, open at the end, rather long and unequal in size, 



E 



