NO. 3 CASSIDULOID ECHINOIDS — KIER 185 



(1948, p. 246) maintained it as a separate genus, he thought it very 

 similar to Rhyncholampas. Unfortunately, I was not able to locate 

 any specimens of the type species in the Paris museums, but from a 

 study of Cotteau's figures and an examination of the holotype of 

 Rhyncholampas thieryi Lambert, a species Lambert and Thiery con- 

 sidered congeneric with the type species, Galerolampas appears to be 

 a synonym of Rhyncholampas. It has the same petal arrangement, 

 similar shape, transverse pentagonal peristome, well-developed flos- 

 celle, and naked medial zone in interambulacrum 5 and ambulacrum 

 III typical of Rhyncholampas. It differs only in having a slightly 

 inframarginal periproct, whereas in most species of Rhyncholampas 

 the periproct is either marginal or slightly supramarginal. This dif- 

 ference does not seem of sufficient importance to warrant generic 

 distinction. 



? Synonym of RHYNCHOLAMPAS 



Gisopygus Gauthier, in Fourtau, 1899. Mem. Inst, figypt., vol. 3, p. 648. Type 

 species, Rhynchopygus naviUei De Loriol, by subsequent designation, Lambert 

 and Thiery (1921, p. 365). 



Remarks. — I have not seen any specimens of the type species of 

 this genus. As no drawings have ever been published of the structure 

 of the phyllodes, it is not possible to know for certain the generic 

 affinities of this genus. Both Lambert and Thiery (1921, p. 365) and 

 Mortensen (1948, p. 252) considered this genus a synonym of 

 Eiirhodia. Its test, however, is not as elongate nor its adoral surface 

 as flat as in Eurhodia. It seems very similar to Rhyncholampas, and 

 is herein considered provisionally as a synonym of it. 



Synonym of RHYNCHOLAMPAS 



Plagiopygus Lambert, 1898. Bull. Soc. Beige Geol., ser. 2, vol. 11, p. 162. 

 Type species by original designation, Nuclcolites grignoncnsis DeFrance. 

 Lambert and Thiery (in Lambert, 1913) proposed a substitute name, Pleuro- 

 pygus for Plagiopygus, considering the latter to be preoccupied by Plagiopyga 

 Boheman, 1848. However, since the names arc not exactly the same, Lam- 

 bert's Plagiopygus can be maintained, and Plcuropygus is a junior objective 

 synonym of Plagiopygus. 



DESCRIPTION OF TYPE SPECIES 

 RHYNCHOLAMPAS GRIGNONENSIS (DeFrance) 

 Plate 28, figures 4-8; text figures 151, 152 

 Nuclcolites grignoncnsis DeFrance, 1825. Diet. sci. nat., vol. 35, p. 214. 



Material. — Two specimens studied in the collections of the ]J. S. 

 National Museum, and several, including Cotteau's figured specimen, 

 in the ficole National Superieure des Mines, Paris, 



