124 THE FOSSIL ECHINOIDEA 



Dimensions. Diameter of the test 18 millim. ; height 11 miillim. ; peristome 

 6 millim. 



Locality. Gagar Nala, near the Darwat, on the Baran. (Khirthar series of strata.) 



rj , G302 



burvey-number -^^. 



Illustrations of the 8jpecies in Plate XXII. 



Fig. 13. Profile view of the test : magnified twice. 



14. Ambulacral and interambulacral plates : magnified. 



OreZer ECHINOIDEA EXOCYCLICA. 



Suborder GNATHOSTOMATA. 

 Family CONOCLYPEID^. 

 Genus CONOCLYPEUS, Agassiz, 1840 (amended). 



(See anted, p. 51, Part ii.) 



1. CoNOCLTPEUS ALVEOLATUS, Bwncan 8f Bladen. Plate XXIII, Figs. 1-6. 



The test is of large size, marginal contour oval, slightly protruding posteriorly, the 

 breadth being about eight ninths of the length. The height is nearly two thirds of 

 the length, and the apical summit is rather excentric anteriorly. Seen in longitudinal 

 profile, the dorsal convexity approaches a subconoid outline,, but with the apex well 

 rounded, and the anterior slope straighter and less curved than the posterior; the 

 odd posterior interradium is also slightly tumid or subcarinate along its median 

 line, approaching to a subrostrate prominence at the posterior extremity. The actinal 

 surface is flat, very faintly impressed round the peristome, and the margin, though 

 comparatively sharp, is well rounded. 



The apical disk is large. There are four genital pores ; and the whole of the 

 extensive central portion of the system is punctured with the pores of the madreporite. 

 The ocular plates and pores are exceedingly minute and do not encroach on the madre- 

 poriform body. 



The ambulacral petals are broad and equal, very widely open at the outer 

 extremity, and with no tendency to converge. The upper portion of each of the petals 

 is sunken in a well-defined depression of the test, which gradually disappears, however, 

 towards the outer fourth of the petal, where the interporiferous zone is flush with the 

 rest of the test, the petals reaching almost to the margin. This depression of the 

 ambulacral areas gives a very prominent and almost gibbous character to the interradial 

 portions of the test on the upper portion of the abactinal surface. The poriferous 

 zones are very broad, the width increasing gradually from the apex to the inner third 

 of the petal, and then decreasing slowly up to the outer extremity. The outline formed 



