NOTES ON THE LISTS OF MOLLUSCA. I13 



Phlyctis, Harris and Burrows. 



Syn. Phlyctcenia, Cossmann, 1881 {tioii Hiibner, 1816). 

 Derivation^ (pXvk-ic, a blister. 



Bathytoma, Harris and Burrows. 



Syn. DoUchotoma, Bellardi, 1875 {iiott Hope, 1839). 

 Derivation, jyadvc, deep ; ro^//, cut, notch. 



AsTHENOTOMA, Harris and Burrows. 



Syn. Oligotoma, Bellardi, 1875 {non Westwood, 1836). 

 Derivation, atrdtin'jQ, weak, slight ; ru/d)), cut. 



Peratotoma, Harris and Burrows. 



Syn. Homotonia, Bellardi, 1875 {non Guerin-Meneville, 

 1829-1838). 

 Derivation, Tripag, end, boundary ; To/jt'i, cut. 



LiocARENUS, Harris and Burrows. 



Syn. Fortisia, Bayan, 1870 (//w/ Rondani, 1861). 

 Derivaiiofi, Xeim^apijioQ, bald-head. 



MiCRELASMA, Harris and Burrows. 



Syn. Ane/as/na, Cossmann, 1889 (non Darwin, 185 1). 

 Derivation, jjuKpoq small ; eXa/ridu, a thin metal plate. 



Spartina, Harris and Burrows. 



Syn. Tlianniasia, Albers, 1850 {noji Perty, 1830- 1834). 

 Derivation, (nrap-iyri, a rope of esparto-grass. 



When two generic names differ only in their terminal letter or 

 letters, it is considered by some authors that only the first of these 

 two names should stand. For instance, Mr. E. A. Smith has 

 discussed this point in the Journal of Conchology (1891, p. 336), 

 with reference to Hydrobia, and has replaced that name by 

 Pahidestrina, on the ground that it is pre-occupied by Hydrohius 

 of Leach. Mr. R. B. Newton, too, in the Geological Magazine 

 (189 1, p. 202), has discarded Leveille's Porcellia because Latreille 

 called an Isopod Porcellio. Had we held similar views, it would 

 have been incumbent on us to re-name many other genera than 

 those cited above. Though we cannot commend such names, 

 still they seem to us sufficiently distinct, especially when, as in the 

 above instances, they designate genera in different zoological 

 groups. Since, moreover, opinions are divided on this matter, we 

 have preferred to await the adoption of a more definite rule than 

 now obtains, rather than to coin new names which might have 

 eventually to be abandoned. The principles on which we have 

 proceeded throughout are well expressed by Profs. Cope and 

 Kingsley in the American Naturalist for July, 1891, vol. xxv, 

 p. 640. 



