NO. 3 CASSIDULOID ECHINOIDS — KIER 1 55 



Apical system. — Small, very eccentric anteriorly, tetrabasal, but 

 owing to poor preservation, no other details visible. 



Ambulacra. — Petals short, narrow, with slight tendency to close 

 distally; interporiferous zones almost twice width of poriferous 

 zones; pores conjugate, outer pore slightly elongate transversely. 

 Petals II and IV transverse or curving posteriorly. Ambulacrum III 

 not petaloid, arrangement of pore pairs not clear on specimen studied. 



Pcriproct. — Inframarginal, longitudinal. 



Peristome. — Slightly anterior, partially destroyed in specimen 

 studied, but from d'Orbigny's figure (1856, pi. 909, fig. 8), slightly 

 longitudinal. 



Floscelle. — Bour relets present; phyllodes broad (text fig. 127 for 

 A. saadensis), double pored with approximately six pore pairs in 

 each outer series and three or four in the inner series in each half- 

 ambulacrum ; no buccal pores. 



Occurrence. — Cretaceous (Cenomanian) at Fourras, Charras, and 

 Port-des-Barques (Charente-Inferieure), France; Djebel Maghila, 

 Foum-el-Guelta ; Djebel Cehela, Tunisia ; Ain Baira and Bou-Saada, 

 Algeria. 



Location of type specimen. — Holotype apparently lost, but plaster 

 cast in Museum d'llistoire Naturelle, Neuchatcl, Switzerland (Lam- 

 bert and Jeannet, 1928, p. 198). 



Genus GENTILIA Lambert 



Gentilia Lambert, 1918. Mem. Soc. Acad. Aube, ser. 3, vol. 55, p. 35. Type 

 species Gentilia fafileltensis Lambert by subsequent designation Lambert 

 (1920a, p. 154). 



Synonym : Thomasastcr Lambert. 



GENERIC DESCRIPTION 



Medium size, usually inflated, greatest width posterior, slightly 

 pointed posterior margin, steep sides, flat adoral surface ; apical sys- 

 tem anterior, tetrabasal ; petals very broad, closed distally, unequal, 

 petal III absent or very short, interporiferous zones very broad, 

 poriferous zones narrow, pores conjugate, outer pore slitlike; peri- 

 proct inframarginal, large, slightly longitudinal; peristome longi- 

 tudinal, flush with test ; bourrelets slightly developed ; phyllodes wid- 

 ened, single pored with two series of pores in each half -ambulacrum ; 

 buccal pores absent or slightly developed ; adorally tubercles approxi- 

 mately same size as adapically, very narrow naked granular zone in 

 interambulacrum 5. 



