NO. 3 CASSIDULOID ECHINOIDS — KIER 65 



places, particularly marginally and in the right anterior portion of 

 the adapical surface. The peristome is covered with matrix. 



Shape. — Small, holotype only 19 mm, long, probably an immature 

 specimen, oblong, low, with greatest height anterior to center. 



Apical system. — Anterior, tetrabasal, oculars large, posterior ocu- 

 lars in contact with each other ; madreporite large ; four genital pores. 



Ambulacra. — Petals broad, open, approximately equal in length, 

 petals II, III, and IV extending almost to margin, petals I and V 

 extending two-thirds distance to margin. Interporiferous zones broad, 

 almost twice width of poriferous zones. Pores conjugate, outer pore 

 slitlike, inner round or slightly elongated transversely. 



Periproct — Supramarginal, approximately two-thirds distance from 

 apical system to posterior margin, longitudinal, in slight groove. 



Peristome. — Covered with matrix. 



Floscelle. — Covered with matrix but phyllodes probably double 

 pored as typical in Nucleolites. 



Occurrence — ? Upper Cretaceous (Senonian) at Djelfa, Algeria. 



Location of type specimen. — Holotype in Lambert Collection at 

 the Sorbonne, Paris. 



Genus PSEUDOSORELLA Etallon 



Pseudosorella Etallon, 1859. Mem. Soc. Emulation de Montbeliard, vol. 3, 

 (1858), pp. 415-416. Type species by monotypy, Desoria orbignyana Cotteau. 

 Cotteau (1862) and all subsequent authors have used the spelling "Pseudo- 

 desorella" for this genus. Etallon's spelling of the word is evidently not a 

 typographic error since he spells it Pseudosorella in both instances in which 

 the name is used. He combined "pseudo" and "desorella" and presumably 

 dropped the "de" for simplicity. This original spelling must be used. 



Synonym : Neoclypeus De Loriol. 



GENERIC DESCRIPTION 



Medium to large, broad, inflated, with rounded margin, adorally 

 ambulacra depressed ; apical system central to slightly anterior, tetra- 

 basal ; petals broad, long, extending almost to margin, with wide 

 interporiferous zones, narrow poriferous zones, open or with slight 

 tendency to close distally, pores conjugate, outer pore elongated into 

 slit, inner round ; all ambulacral plates double pored ; periproct supra- 

 marginal, in contact with apical system, in deep groove extending 

 from apical system to margin ; peristome central or slightly anterior, 

 pentagonal, wider than high ; bourrelets present ; phyllodes well de- 

 veloped, slightly broadened, double pored, with many pore pairs in 

 two series in each half -ambulacrum; no buccal pores. 



