OF WESTERN SIND. 257 



Order ECHINOIDEA EXOCYCLICA. 



Suborder GNATHOSTOMATA. 

 Family CLTPUASTBIDJE. 



Subfamily EUCLYPEASTRIN.S. 



Genus CLYPEASTER, LamarcJc, 1801. 



1. Cltpeaster simplex, Duncan & Sladen. Plate XL, Figs. 1 & 2. 



The test is pentagonal in outline, with the posterior angles truncated and the 

 anterior angle rather acute ; the lines of the sides are slightly inclined to the posterior 

 angle, and the posterior edge is nearly straight and rather narrow. 



The length is greater than the breadth, and the test is depressed, rising gradually 

 from the rather sharp margins to the apex. Actinally there is considerable concavity, 

 and the ambulacral lines there are well marked. Peristome not visible. Periproct 

 small and near the edge. The petals are broad and long, hardly tumid, and rather 

 tend to close. They are equal in length and extreme breadth inter se, and the only 

 distinction is that the anterior is perhaps -5 millim. the longest ; their shape does not 

 differ, and none are swollen. 



The poriferous zones are broadest in the outer third, and diminish rather rapidly ; 

 they tend to close, and the left anterior (zone b) overlaps slightly the right one (zone a). 

 The closing is not perfect in any one. The outer pores are the largest, and are more 

 elliptical than those of the inner row. 



Dimensions. Length 64-5 millim., breadth 59 millim., height 15 millim. 



Locality. Nari series (Oligocene). Baran-River section, eight miles below Tong. 

 Survey-number G ^-- 



Illustrations of the Species in Plate XL. 



Fig. 1. The test, from above. 



2. Longitudinal outline of test. 



2. Cltfeastee, sp. Plate XXXIX, Figs. 13 & 14. 



Some small specimens of Clypeaster of the Clypeaster-depressus, Sowerby, type, but 

 differing somewhat from that species, are in the collection. They are not suflBciently 

 preserved to describe fully, and therefore we have drawn what can be seen. 



Localities. Nari (Oligocene). Baran-River section, eight miles below Tong, and 

 from a high bed : and Trak, seventeen miles south of Bula Khan. Survey-numbers 



G2 2.5. a. 2. 8. 0. 

 "6 2 5'^ 54 • 



Illustrations of the Species in Plate XXXIX. 



Fig. 13. A specimen, abactinal view. 



14. The same, from the actinal surface, 



2m2 



