some Species referred to it. 49 



no genotype for any of the other genera, wliether new or old, 

 discussed by hira. He mentioned E. heyserlingi by name 

 because it was the form next to his hand, and it was not his 

 purpose to investigate all the other species of the genus ; or, 

 to look at the matter from the other side, he used the name 

 Eocidaris for his new generic concept merely because he 

 found the name already in use*. But, even assuming that 

 he did mean to fix on C. heyserlingi as the genotype of 

 Eocidaris Desor, T maintain that he was prevented by the 

 prior action of Qiienstedt, who had seized on the essential 

 point and removed C. heyserlingi from Eocidaris. 



In coming to this conclusion, I am glad to find myself 

 essentially in accord with Dr. A. Tornquist, who, since he 

 too hailed from Strassburg University, was doubtless familiar 

 with the views of his colleague. In 1896 (p. 38) he dis- 

 cussed the validity of Eocidaris, and once again pointed out 

 tiiat C. hyserlingi was a true Cidarid. But to interpret 

 Eocidaris by C. keyserling), and to place it in tlie Cidaridae, 

 as Zittel had done (1895, p. 186), was, he maintained, far 

 from Desor's intention. Eocidaris must remain in the 

 Archgeocidaridge; that there really did exist forms corre- 

 sponding to the diagnosis of Desor, had been proved by the 

 American Eocidaris drydenensis and Lepidocidaris squamosa, 

 while European representatives were Eocidaris scrvhiculata 

 and E. verneuiliana. As for Cidaris rossica, though some of 

 its interambulacrals, notably in the adambulacral columns, 

 were devoid of a basal terrace, and therefore of Eocidaris type 

 as Desor supposed, others had that structure and therefore 

 justified the reference of the species to Archceocidaris 

 { = Echinocrinus). Both here and in a later paper (1897, 

 p. 48 = 770), Dr. Tornquist showed a strong inclination to 

 interpret Eocidaris in the light of E. drydenensis. But this 

 species, being unknown to Desor, could not be taken as geno- 

 type. Essentially, then, Tornquist confirmed Quenstedt, by 

 transferring C. rossica and by eliminating G. keyserlingi : 

 *'fiir diese ist allenfallseine neue Gattung aufzustellen, wenu 

 man sie nicht mit Cidaris vereinigen will.^'' 



So far as Eocidaris was concerned, the same position was 

 taken up by that very learned writer on fossil Echinoids, 

 Mr. J. Lambert (1900, p. 38). Having pointed out that 

 E. heyserlingi, E. verneuiliana, and E. rossica did not agree 

 in essential points with Desor's diagnosis, he referred them 



* The International Code of Zoological Jsomenclature (1907) says 

 under Article 30, rule ff : "The meaning of the expression 'select a 

 type ' is to be rigidly construed. Mention of a species as an illustration 

 or example of a genus does not constitute a selection of a type." 



Ann. <& Mag. N. Hist. Ser. 8. Vol. iii. 4 



