NO. 3 CASSIDULOID ECHINOIDS — KIER 2I3 



GENERIC DESCRIPTION 



Medium to large, elongate, low to moderately inflated; adorally 

 flattened, apical system monobasal; petals equal, broad, closing dis- 

 tally, ambulacral plates beyond petals single pored; periproct supra- 

 marginal, transverse or longitudinal; peristome higher than wide; 

 bourrelets strongly developed; phyllodes broad, single pored, with 

 two series of pores in each hal f -ambulacrum ; buccal pores present; 

 tubercles perforate, considerably larger adorally than adapically, ex- 

 cept for naked and often pitted adoral interambulacrum 5, 



Comparison with other genera. — This genus is not very distinctive. 

 Its most distinctive feature is its elongate shape and higher than wide 

 peristome. Mortensen (1948, p. 254) suggested that the genus should 

 be restricted to only those species having a higher than wide peri- 

 stome, and posterior petals in which the posterior poriferous zones 

 are reduced. This latter feature is known only in the type species 

 and does not seem of generic importance. 



Desor's Cassidulus amygdala should be referred to Eurhodia. It 

 has the elongate test, supramarginal periproct, higher than wide 

 peristome so typical of Eurhodia. I studied two specimens of this 

 species in the Cotteau Collection at the £cole National Superieure 

 des Mines in Paris. 



Cooke (1961, p. 21) transfers Jeannet's (1928, p. 32) Eurhodia 

 falconensis to Cassidulus. I have seen the holotype in the Natur- 

 historisches Museum, Basel, Switzerland, and agree with Cooke that 

 it is not a Eurhodia. Its test is not sufficiently elongate, and its 

 peristome is wider than high. 



Range and distribution. — Palcocene-Eocene of India, Europe, 

 North Africa, Madagascar, and North America. 



DESCRIPTION OF TYPE SPECIES 



EURHOriA MORRISI Haime 

 Plate 40, figures 6-9; text figure 176 



Eurhodia viorrisi Haime, in d'Archiac and Haime, 1853. Descr. animaux foss. 

 Inde, p. 214. 



Material. — Ten topot^^pic specimens were studied from the Museum 

 of Paleontology, University of California, Berkeley, Calif. New 

 photographs were sent from India of the t>'pe specimen. 



Shape. — Medium size, low, very elongate, posterior truncate, 

 greatest width anterior to center, greatest height posterior. 



Apical system. — Monobasal, anterior. 



