OF WESTERN SIND. 309 



the small imperforate mamelon. In the space between the consecutive tubercles there 

 is a row of two or three rather large granules in a transverse row. Between the 

 tubercles and along the median line of the area there are a few rather indistinct large 

 and small granules united to the base of the great tubercle by costa-like ridges. Some 

 granules situated at the actinal and abactinal edges of the plates are often connected 

 to the tubercles by the ridges. 



The arrangement of the tubercle-bearing triplet of ambulacral plates is as in the 

 generic definition. 



The interradia are broad between the apex and the peristome, and the plates of 

 the part above the ambitus are with a median and adorally projecting angle, the usual 

 generic scale-like appearance being very decided when there has been some weathering. 

 The sutures are distinct and sunken, and the primary tubercles are in a vertical row, 

 there being a tubercle in the centre of every one plate of the interradia, with a large 

 base and a small mamelon. Just above the ambitus the rest of the plate unoccupied 

 by the large tubercle is closely packed with rounded granulations, some of which are 

 between the poriferous zone and the tubercle. These last are united to the small costse 

 of the poriferous zone. At the actinal surface the great tubercle of a plate has the 

 granules more or less in ill-defined circles around it, and there is often a costulation 

 between them. The tubercles of the interradia are rather larger than those of the 

 ambulacra; but both sets are small. The radiation of the costa-like processes is often 

 visible from a tubercle close to the peristome to the granules between it and the 

 poriferous zone of the ambulacrum. There are fifteen plates on one side of an inter- 

 radium, and three times that number of large and demi plates belonging to the 

 ambulacra. 



Dimensions. Height 7 millim., breadth 11 millim. 



Locality. The Gaj or Miocene series of Sind : Mazarani Nai. Survey-number 



n. 298 

 " 5 • 



The arrangement of the plates of the interradia and ambulacra, the character of 

 the apical disk, the small peristome with very slight cuts, the sunken sutures seen in 

 some places, and the costa-like union of the tubercles and granules link this form with 

 the last. 



The distinctions of a specific character are the multigranular plates above the 

 ambitus without costal unions, the simpler ornamentation of the ambulacra in the 

 median line, and the presence of a third intermediate granule. The shape of the test 

 also adds to the differences between the two species. 



