NO. 3 CASSIDULOID ECHINOIDS — KIER 205 



type is herein designated to be the specimen figured by Duncan and 

 Sladen (op. cit., pi. i6, figs. 1-7). New photographs of this specimen 

 were sent me by the Indian Geological Survey. 



Shape. — Medium size, lectotype 34 mm. long, margin rounded 

 anteriorly, pointed posteriorly, broad, highly inflated with greatest 

 height posterior to center, steep sides, flat adoral surface with flush 

 peristome. 



Apical system. — Anterior, monobasal, four genital pores. 



Ambulacra. — Petals well developed, broad, closed, slightly inflated, 

 equal length, extending two-thirds distance to margin ; interporif- 

 erous zones twice width poriferous zones at greatest width ; porif- 

 erous zones broad, pores strongly conjugate, outer pore elongate, 

 situated oblique to inner pore with inner pore nearer apical system ; 

 plates beyond petals single pored. 



Periproct. — On top of posterior prolongation, small, oval, infra- 

 marginal, slightly overhung by adapical surface. 



Peristome. — Pentagonal, transverse, anterior, flush with test. 



Floscelle. — Bourrelets well developed, forming rim around peri- 

 stome ; phyllodes (text fig. 169) widened, single pored, flush with 

 test, with three longitudinal series of pores in each half area, 10 to 

 12 pores in each outer series, 2 to 4 in the middle, 6 to 8 in each 

 inner series; plate sutures visible around inner pores; buccal pores 

 present. 



Tiiherculation. — Adorally, tubercles slightly larger than adapically ; 

 apparently no naked sternal area but region not well preserved on 

 any specimen studied by this author. 



Occurrence. — Paleocene-Ranikot Series, India. 



Location of type specimen. — Geological Survey of India, Calcutta, 

 India (personal communication from V. R. Khedker). 



Remarks. — Duncan and Sladen state that the periproct is supra- 

 marginal, but in the new photographs, and their figures of the lecto- 

 type, and in all the other specimens I studied, the periproct is low 

 on the posterior margin and visible from below. 



Genus ILARIONIA Dames 



Ilarionia Dames, 1878. Palaeontogr., vol. 25, p. 34. Type species by monotypy, 

 Echinanthus beggiatoi Laube, 1868. 



GENERIC DESCRIPTION 



Medium size, elongate, inflated with steep sides, flat adorally; 

 apical system anterior, monobasal, four genital pores; petals broad, 



