Il6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I44 



Periproct. — Inframarginal, large, transverse. 



Peristome. — Anterior, large, transverse, subpentagonal. 



Flosccllc. — Bourrelets forming a flange around peristome. Phyl- 

 lodes not broadened, with slight crowding of pores, single pored; 

 buccal pores. 



Tuherculation. — Tubercles large, of approximately same size ad- 

 orally as adapically, scrobicular ring large, with approximately 15 

 scrobicular tubercles in each ring; boss small, perforate. 



Occurrence. — Eocene at Saint-Gilles, Belgium. 



Location of type specimen. — Musee Royal d'Histoire Naturelle 

 de Belgique, Brussels, Belgium. 



Remarks. — If Cotteau's description and figures of this species had 

 been correct, and if they had been based on adult specimens, then 

 Pomel would have been correct in erecting a new genus for it. The 

 lack of a petal in ambulacrum III, absence of petaloid pores in the 

 anterior poriferous zones of petals II and IV, the high globular test, 

 and the five genital plates are characters of sufficient importance to 

 distinguish generically this species from any other species known. 

 However, these characters either do not occur in this species, or, in 

 my opinion, are immature characters which would not be found on 

 an adult of this species. Cotteau states in his description that the 

 apical system has four genital plates, but in his figure shows five. 

 Pomel did not see the specimen, but stated, presumably after study- 

 ing Cotteau's figures, that there were five genital plates. I was able 

 to study the holotype, and only known specimen of this species, 

 under high magnification, and without doubt the apical system is 

 monobasal. I believe that all the other characters that would gener- 

 ically distinguish this species are immature and that this species is 

 an Echinolampas, and probably an Echinolampas affinis (Goldfuss). 

 One would expect a young specimen of an Echinolampas to look 

 exactly like the holotype of E. lehoni. The following features of 

 E. lehoni are also found in the young of Echinolampas fraasi De 

 Loriol as described by Kier (1957, p. 849) : The most obvious and 

 striking evidence of immaturity is the lack of genital pores. Cotteau 

 in his description says that the genital plates are perforated but in 

 his figures shows them to be imperforate. I examined the apical 

 system with high magnification both dry and immersed in alcohol, 

 and there are definitely no genital pores. In E. fraasi genital pores 

 do not occur on any specimens less than 14 mm. long (the holotype 

 of E. lehoni is 9.5 mm. long). In E. lehoni as in the young of 

 E. fraasi there are very few madreporic pores, and the apical system 



