OF WESTERN SIND. 253 



the apical system downwards, and at the ambitus the inner pore of each pair is within 

 the line of the circumference of the base of the tubercle close by. The lower pair 

 of the triplet is at the lower edge of the tubercle, and a little more towards the median 

 line than the others. 



In well-preserved specimens there is on every plate which carries a large primary, a 

 smaller tubercle, and it is placed (Plate XXXIX, Fig. 6) near the adoral and outer edge. 

 Above the ambitus, where the larger tubercles cease, the secondary persists on each 

 plate and occupies the same; relative position as elsewhere (Fig. 5). 



The interradial tubercles diminish in size above and below the ambitus, and there 

 are two visible from above. The greater part of the median surface above the tubercle- 

 bearing plates is plain. There are zigzag lines, and there is an ornamentation on each 

 plate, which, starting from the vertical miliary and tuberculate edge on the outer 

 third, forms angular ridges and grooves which impinge on the median sutural lines, 

 and unite these with those of the opposed plates (Fig. 5). The ornamentation of the 

 outer third of the plate consists of a narrow raised vertical ridge of elongate granules ; 

 beyond this is a vertical row of distant small secondaries, one tubercle being placed 

 on the lower and outer angle of each plate. Between these secondaries are a few 

 large miliaries, sometimes in rows of threes or fours. It is this row of small tubercles 

 which characterizes the species. Usually there is but one small tubercle on each plate, 

 but towards the ambitus there may be two, but this is not universal. There is more 

 miliary tuberculation between the tubercles at the ambitus and lower down for a short 

 space than elsewhere. All the primary and secondary tubercles have a broad base, 

 no sunken scrobicule, and a small projecting mamelon. The lowest of the vertical 

 row of secondaries is small, and it is turned slightly out of its line by the existence of a 

 long angular tag or continuation of the peristomial cut. Each tag extends up the 

 ambulacrum as high as the third set of triplets, and is marked by some of the sutures 

 of the poriferous plates. Between the primaries of the interradia there is a small row 

 of miliaries ; it extends along the median and partly transverse sutural lines. 



Dimensions. Height IG millim., length 27 millim. 



Locality. Nari series, Oligocene of Sind. West side of Bhagothoro Hill, south of 

 Sehwan. Survey-number G-^^. 



Illustrations of the Species in Plate XXXIX. 



Fig. 3. The test, abactinal view. 



4. The side view. 



5. Interradial plates, lower part of 4th and the whole of the 5th 



from the apex : magnified. 



6. Interradial plate at ambitus : magnified. 



7. The triplets of pores and an ambulacral tubercle, actin3,l surface. 



8. The apical disk: magnified. 



