26 THE FOSSIL ECHINOIDEA 



the mamelon being small and perforate. The crenulation is distinct in the groove at 

 the base of the mamelon, but it does not pass over the sides of the boss. There are 

 from 8 to 10 pairs of tentaculiferous pores in relation to a large interradial plate. 



Locality. Kanikot group, north by east of Petiani, west of Kotri. Survey- 

 number G yf f . 



Illustrations of the Specimens in Plate V. 



Fig. 1. An interradial plate : magnified. 



2. A section of a plate : magnified. 



3. A portion of an ambulacrum : magnified. 



2. CiDARis Veexeuili, dJArcJiiac. Plate V, Figs. 6-8. 



Cidaris Verneuili, cVArchiac, 1850, Hist, des jarogres de la Geol. t. iii. p. 246. 



, d'Archiae Sf Haime, 1853, Descrip. Anim. foss. de I'Inde, p. 195, pi. xiii. figs, la & 16. 



Some large plates probably belong to this perforate non-crenulate form. 



In the largest plate (Fig. 7) the scrobicular area occupies the larger part of the 

 plate, and is separated from the sutural lines above and below, by the secondary 

 tubercles of the circle and a few smaller ones beyond. These secondary tubercles are 

 small, rather wide apart, and have bosses and mamelons. Beyond there is a circle of 

 much smaller tubercles, which are also rather wide apart, and beyond there are 

 irregular rows of large miliaries extending to the edges of the plates with suture-like 

 lines between them. The whole of this ornamentation is on a convex surface which is 

 slightly higher than the scrobicular area. The boss slopes gradually upwards and has 

 a Avide top, and a circular furrow is around the base of the mamelon. This has a 

 constricted neck, a depressed convex top, and is largely perforate. 



The width of the largest plate is f inch ; height -^g inch. 



Locality. Kanikot series, north-east of Petiani, west of Kotri. Survey-number 



n 2.8^0 

 ^ 135- 



Illustrations of the Species in Plate V. 



Figs. 6 & 7. Plates of Cidaris Verneuili : natural size and magnified. 

 8. A section of a plate (Fig. 7). 



Subgenus PHYLLACANTHUS, Brandt, 1835. 



Alexander Agassiz has pointed out that this subgenus has precedence of 

 Ehahdocidaris of Desor. The group belongs to the genus Cidaris, and the subgeneric 

 characters are broad interporiferous zones, pores conjugate, tubercles crenulate and 

 perforate. 



