62 THE TERTIAKY FOSSIL ECHINOIDEA 



is less than that of the other petals, but approaches that of the postero-lateral pair. 

 The left-hand poriferous zone is slightly the shortest. 



The antero-lateral ambulacra are yery nearly transverse and broader than the 

 others ; they are lanceolate near the apex, but near the margin the anterior poriferous 

 zone (the shorter of the two) turns backwards, whilst the posterior and longer continues 

 its path, turning very slightly posteriorly when nearer the margin than the other. 



The postero-lateral ambulacra, narrower than the antero-lateral, are slightly the 

 longest, for their anterior poriferous zoneis-continued on beyond the posterior by ten or 

 twelve pairs of pores, and this part of the zone tends to turn slightly forwards at the 

 end. The pairs of pores of the ambulacra are rather wide apart. The ornamenta- 

 tion of the interporiferous areas is very close, and it is in transverse linear series in 

 lateral ambulacra. 



Behind the apex the test is much less tumid than in front ; and the ornamentation 

 is small, close, and uniform over the whole abactinal surface. 



The periproct is submarginal and rather obliquely placed; it is elliptical and 

 elongated transversely, and is visible from behind in young specimens. 



The ornamentation of the interradia is crowded and small, widest near the apex 

 and ambitus. 



The ornamentation on the actinal surface is nearly twice the size of that above, 

 as well as more distant and distinct. 



Measurements of type : — Length 55 millim., breadth 49, height 30. 



Ditto of a large form : — „ 65 „ „ 56, „ 34. 



Distance of apical system from the front in type 11 millim., and in the large 

 specimen 15 millim. 



Eelative dimensions : — Length 1, to breadth 0-89, to height 0-54. 



„ 1, » 0-86, „ 0-52. 



Locality. Miocene series of Kachh: Wamuti. Survey-numbers C 190, C 190 f. 



Illustrations of the Species in Plate IX, 



Fig. 1. Abactinal view : natural size. 



2. Side view. 



3. Actinal view. 



4. A specimen with narrower petals. 



5. Abactinal view of the same. 



6. Apical system, magnified, of Fig. 1. 



7. Peristome: magnified. 



8. A variety : abactinal view. 



9. A variety : actinal view. 



10. Part of a phyllode : magnified. 



