BY H. L. KKSTEVKN. 79 



he has since placed in the genus Septa- When describing C . 

 puniilio he wrote: "The nearest relation is L. bassi Angas, 

 with which it agrees in the small number of its whorls, colour, 

 sculpture and general appearance." After comparing — at 

 my request — C. pefulans, C. pumilio, and C. parkinsonianuni , 

 Mr. Hedley expressed the opinion that, in the adult shells, 

 there were no features on which to divide these species generi- 

 cally. C. parkinsonianiun finds no place in my "tritonis 

 group" (27), that is in the genus Septa Perry-Dall. 



Whilst adopting my "groups" of the genus Cyniatium, Dall 

 differs from me in that he has given these groups quotable 

 names, assigning them varying sectional values. When one 

 remembers the divergence of opinion in the past among 

 authors, in assigning the species to the various groups, such a 

 procedure seems rather courting confusion, for the adoption 

 of the sectional names would lead to many species being 

 assigned now to one section, now to another- On one other 

 point does Dr. Dall differ from me ; he proposes to separate 

 my "group of C. quoyi" from Cymatiuni as a full genus 

 under the name of Personella Conrad. To those familiar with 

 the species of the group, such a proceeding would not seem 

 desirable or justifiable. Hedley recently described a "Cyrjia- 

 tium columnari'uyn ," which, he says, "stands nearest to C. 

 quoyi Reeve, from which it differs by being thinner, more 

 slender and with weaker sculpture." Dr. Dall {suh voce Per- 

 sonella) writes: "Type P. septemdentata Gabb. Eocene- 

 Recent analogue, Triton qiioyi Reeve." Hedley (I.e.) refers 

 to Dall's proposition, but does not assign his species to Per- 

 sonella. 



Dall is undoubtedly correct, in considering that, in the 

 arrangement of the members of this group, "the dentition, 

 the protoconch and nepionic shell and the operculum must all 

 be considered," also that adult conchic characters are not 

 altogether devoid of taxonomic value. Of these four charac- 

 ters, the operculum is neutral, the protoconch and nepionic 

 shell, and the adult conchic characters point to the natural 



