88 THE TERTIARY FOSSIL ECHINOIDEA 



but very small near the apical system. The pores of the odd ambulacrum are also 

 visible. 



Locality. Kattywar Miocene. Three miles east by north of Gaga, and south-east 



of Gurgat. Survey-number ^. 



Genus SCHIZASTER, Agassiz, 1836. 



1. SCHIZASTEE GeANTI, VloMs. 



This is the commonest fossil in the collection from Kattywar, and some of the 

 specimens are larger than the type from Kachh (page 70). The specific characters 

 are, hov^ever, well maintained ; and it is noticed that even in the largest specimens 

 the keel on the posterior interradium is low, and that it slopes backwards and down- 

 wards to the point which overhangs the periproct. The anterior groove is broad and 

 deep abactinally, and is shallower and less evident in front of the curved fasciole. 



The anterior ambulacral pores are separated by a nodule, and they are on the flanks 

 of the groove. The pairs of pores have a more or less definite swelling like an indefinite 

 costa between them ; and the floor and sides of the groove are very granular, the larger 

 tubercles being near the top of the keel on eitlier side. 



The antero-lateral ambulacra flare outwards, are in deepish grooves, and become 

 more or less pointed distally. The obliquity of the pores is not so evident as in the 

 Kachh species, but the granulation of the costse is evident. 



qp.q,q,o ofi^i 



The apical system, magnified. 



The apical system has four generative plates and four pores; the anterior plateS 

 are rather long in the antero-posterior direction, and include the small anterior ocular 

 plate in their angle. The posterior lateral plates are large ; their pores are larger than 

 the others and wider apart. The ocular plates are in the angles of the plates and are 

 well developed; the posterior pair are separated by the madreporic extension. 



The whole apical system is small ; the anterior genital pores are on the anterior 

 keels, and the others on the narrow keel of the lateral ambulacra, which is sparely 

 tuberculate. 



The posterior ambulacra are stout, sharp at the end, shallow, and there are about 

 17-19 pairs of pores. 



