186 STUDIES ON AUSTRALIAN MOLLUSCA, VIII., 



of showing E. ischmis to Mr. W. L. May, and that he recog- 

 nised it as E. simsoni, Tate & May. Of the united names 

 Epigrus ischnus, Tate, takes precedence 



Planaxis brasilianus, Lamarck. 



Several names have been proposed for this species.* Com- 

 mencing with Angas,t writers on Australian MoUusca have 

 unanimously selected Planaxis mollis for employment. Pritchard 

 &, Gatliif 1 alone do so definitely on the ground of priority. But 

 this involves chronological error. Buccinum hrasilianum, 

 Lamarck, § appeared in August, 1822. Planaxis mollis, 

 Sowerby, || was undated on the title page of Part or Volume. 



We learn, however, from NewtonU that Planaxis was included 

 in Part xii. of Sower by's " Genera," and we further ascertain 

 from Sherborn"^* that Part xii. was issued February 3rd, 1823. 

 This, then, is the date to be assigned to Planaxis mollis. 



Those who, like Brazier, ft might prefer P. mollis to P. brasi- 

 lianus, because the latter is a misnomer, are reminded of the 

 rule of zoological nomenclature adopted by the Fifth Inter- 

 national Congress of Zoology : " A name once published cannot 

 be rejected, even by its author, because of inapplicability." 



Sowerby went as far astray in the habitat as Lamarck did, 

 for he considered P. mollis to be a British species. I have 

 already shownit that the type of P. brasilia^ius was apparenth^ 

 collected by a Sydney resident. Suter enlarges the known 

 range of the species by reporting it from New Zealand. §§ 



-^^ Smith, Ann. Mag. Nat. Hist. (4) ix. 1872, p. 46. 

 fProc. Zool. Soc. 1867, p. 210. 

 JProc. Roy. Soc. Vic. n.s. xiv. 1902, p. 87. 



§ Anim. s. Vert. vii. p. 272. 

 II Genera of Shells ii., Explanation to PL 209. 

 •1 Brit. Mus. Cat. Edwards Coll. 1891, p. 321. 

 ** Ann. Mag. Nat. Hist. (6), xiii. 1894, p. 371. 

 tt These Proceedings, (2) ii. 1888, p. 999. 

 :J:J: These Proceedings, xxvii. p. 24, footnote. 

 §§ Index Fauna Novw Zealandiae, 1904, p. 76. 



