228 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I44 



specimens were studied by this author in the Lambert Collection at 

 the Sorbonne, Paris, The specimen figured by Lambert is herein 

 designated the lectotype. Both specimens are badly weathered, with 

 the details of their tests obscured by secondary calcite. The lectotype 

 is 9 mm. long and the paratype 8.5. The test is oval, highly inflated, 

 with rounded adapical surface, and slightly flattened adoral. The 

 structure of the apical system is not clear, but no genital pores are 

 visible. They probably were never present on these specimens, their 

 absence indicating the immaturity of these individuals. Kier (1957, 

 p. 849) found that no genital pores occurred in specimens less than 

 14 mm. long of Echinolampas fraasi De Loriol. There is no indica- 

 tion of petals, their absence again reflecting the immaturity of the 

 individuals. The periproct is inframarginal and transverse, and the 

 peristome is anterior, transverse, with slightly developed bourrelets. 

 No details are visible of the phyllodes. 



It is not possible to know the generic characters of this species, and 

 it is regrettable that Lambert erected a genus for it. I suspect that 

 these specimens may be immature individuals of a species like Clypeo- 

 lampas leskei (Goldfuss). 



Lambert's drawings of the lectotype are inaccurate. According to 

 his figures, the specimen appears to be well preserved and to have 

 petals. I have included photographs of the lectotype (pi. 44, figs. 1-5). 

 Mortensen (1948, text fig. 252) has reproduced Lambert's figures 

 in his monograph but has labeled them as natural size when in reality 

 they are twice natural size. 



Durham and Melville (1957, p. 257) tentatively placed Ovulechinus 

 with Oligopygus because of their general external similarity. How- 

 ever, bourrelets are present in O. pilula, and a floscelle was probably 

 well developed in adult individuals. Ovulechinus is a cassiduloid, 

 whereas Oligopygus is a holectypoid. 



Occurrence. — Upper Cretaceous (Santonian) at Saint Paterne, 

 France. 



Genus PLATIPYGUS De Loriol 



Platipygus De Loriol, 1902. Notes pour servir a I'etude des echinodermes, 

 ser. 2, vol. 10, fasc. i, p. 17. Type species by monotypy, Cyrtoma posthumwn 

 Ortmann. 



Remarks. — I have been unable to locate any specimens of the type 

 species and only known species of this genus. From De Loriol's 

 figures this species looks very much like a Stigmatopygus. For this 

 reason, Lambert and Thiery and Mortensen considered Platipygus 



