100 Annals of tlic South African Museum. 



marine and the other freshwater, which have so long been kept 

 separate, and if the distinction is to be preserved, the name Tiaridae 

 must be introduced. 



With regard to the spelhng, Bolten took his name Thiara from the 

 French thiare, but the classical version, both in Greek and Latin, is 

 Tiara, and as this has been adopted by H. & A. Adams ''- and 

 Geoffrey Nevill, I among other authorities, the omission of the 

 letter "h" is no innovation on my part. 



Melania amarula (Lin.) was included in my " Eevised Eef. 

 List of South African non-marine Mollusca " on the strength of 

 shells from Izezela and Umkomaas, which had been identified with 

 that species. 



I had not seen the examples in question, but, through the kindness 

 of Mr. H. C. Burnup, have now been privileged to examine specimens 

 from the Amanzintoti Eiver, which he assures me are conspecific 

 with those previously mentioned. 



They are far smaller than typical amarula, and the spikes of the 

 tiara are much less pronounced. I hardly think it possible to class 

 them as amarula, Lin., and that species should therefore be 

 removed from the South African list. 



It is now necessary to find a name for these Natal shells. 



They are unquestionably identical with the Melania coacta 

 (iVEeusch.) I of von Martens, § recorded in 1897 from several parts 

 of Zanzibar and the East Coast of Africa, and already included in 

 the South African list, as it was found by Junod in Lorenzo Marques. 



Even if Meuschen's species could be fully recognized, however, his 

 name cannot stand, as the " Mus. Geversianum," in which he pub- 

 lished it, has been ruled inadmissible from a binomial standpoint. 



Brot II and Morch 'f have, on various occasions, associated 

 coacta, Meusch., with M. thiarella, Lam.,*''' but there seems to be 

 no actual proof of their identity, and thiarella, which was described 

 from " Les grandes Indes," seems to be quite distinct from the East 

 African species. 



I think it may hence be concluded that (i) the name coacta, of 

 Meuschen, being published in an inadmissible work, is void, and 

 available for re-empioyment if desired ; (ii) that it had not been 



* Gen. rec. Moll., i. 1854, p. 294. 



t Hand List, ii. 1884, p. 278. 



\ Museum Geversianum, 1787, p. 294 (as Stromhux coactus). 



§ Deutsch-Ost-Afr., 1897, p. 197. PI. VI, f. 36. 



II Conch. Cab., 1877, p. 291. 



1[ J. deC, 1872, xx. p. 319. 



** Hist. nat. An. s. Vert., viii. p. 432. 



