282 THE FOSSIL ECHINOIDEA 



The specimens received from the two last-named localities are too much weathered 

 for positive determination ; they present, however, the chief characters of the species, 

 and we feel little hesitation in referring them to it. 



Illustrations of the Species in Plate XLIV. 



Fig. 1. Abactinal view of the test : natural size. 



2. Profile view of the same test : natural size. 



3. Actinal view of a smaller specimen : natural size. 



4. Ambulacral plates near the ambitus, from the same specimen as Fig. 1 : 



magnified. 



5. Ambulacral plates on the abactinal part of the area, from the same 



specimen : magnified. 



6. Interambulacral plate, from the same specimen : magnified. 



7. Portion of an ambulacral area, to show the flexure and the posture of 



the plates, from the same specimen as Fig. 3 : magnified. 



8. Portion of the margin of the peristome, from the same specimen : 



magnified. 



2. CiDABis EXCELSA, Bimcan & Sladen. Plate XLIV, Figs. 9-11. 



There are two fragments of a Cidaris test, from diflferent localities, in the col- 

 lection of Gaj Echini, which, though unfortunately not well preserved, are still 

 sufficiently marked to indicate that they belong to a species clearly distinct from any 

 known Indian form, and also, we believe, from any hitherto described from other 

 Tertiary areas. 



In both cases the portion preserved consists of nearly the whole of an interambu- 

 lacral area, and in one of the fragments half of the ambulacral area on either side is 

 also intact. The following characters may be observed : — 



Judging from the largest fragment, the test appears to have been high in relation 

 to the breadth of the interambulacral area ; and the tumidity at the ambitus was not 

 great. 



The ambulacra were slightly flexuous and decidedly broad. Poriferous zones only 

 slightly sunken, and narrower than half the interporiferous area. Pores transversely 

 oval, those of a pair equal and similar, placed near together and separated by a 

 small elevation, forming an indistinct granule. There are 12 to 13 pairs of pores 

 opposite one of the large interambulacral plates near the ambitus. The interporiferous 

 areas are broad and ornamented with six longitudinal rows of comparatively widely 

 spaced miliary granules. There are consequently three granules on each plate : that 

 which stands adjacent to the poriferous zone is the largest, mammillated, and occupies 

 nearly the whole of the depth of the plate. The two other granules are quite small 

 and diminutive, little larger than the mamelon of the one just described, widely spaced, 

 and standing near the adoral margin of the plate. The great breadth and apparent 

 nakedness of the interporiferous area is remarkable. 



The interambulacral areas are a little more than three times the width of the 



