Necessity for the Abandonment of the Name Cyclostoma. 345 



Dr. Bcettger, who has lately examined a considerable number, 

 shows that I was probably mistaken in uniting with it the Bor- 

 nean Txalus guttatus, Gthr., which has more or less distinct 

 vomerine teeth. The so-called Ixalus natator is nevertheless 

 no true Ixalus, having the digital structure of Rana latopal- 

 mata, livida, formosa, and guttata, to which it stands in close 

 relation. If the absence of vomerine teeth be considered 

 in this case a valid ground for generic separation, then Ixalus 

 natator must bear the name Staurois natator, which was 

 proposed for it by Cope in 1865; and the name Micrixalus, 

 proposed by me in 1888 for South Indian and Ceylonese 

 species, will become a synonym of Staurois. Whatever the 

 views on this matter may be, Ixalus nubilus of Mocquard is 

 not an Ixalus, and, judging from the description and figure, 

 I can see no reason for separating it from Rana natatrix. 



XXXVI. — On the Necessity for the Abandonment of the 

 Generic Name Cyclostoma, with Suggestions regarding others 

 involved in this Genus. By R. BuLLEN Newton, F.G.S., 

 British Museum (Natural History) . 



Much confusion has existed since Lam arckian days regarding 

 the Molluscan name of Cyclostoma. It was first established 

 by Lamarck in 1799 (Me"m. Soc. Hist. Nat. Paris, vol. i. 

 p. 74), to include the Linnasan type of Turbo scalaris, this 

 same type being afterwards used for his genus Scalaria in 

 1801 (Syst. Anim. sans Vert. p. 88). 



Without a single reference to his genus of 1799 Lamarck 

 again introduces Cyclostoma in his 1801 work, p. 87, this 

 time attaching as its type the Turbo delphinus, Linnosus, 

 which, curiously enough, was made to stand for his genus 

 Delphinula in 1803 (Ann. Mus. Hist. Nat. Paris, vol. iv. 

 p. 108). 



We are thus confronted with the fact that two Linna^an 

 types have been occupied by Lamarck for four of his genera. 

 Priority of nomenclature appears to have been little under- 

 stood in these early times ; and it is one of the difficulties of 

 the modern investigator to unravel this and numerous other 

 inconsistencies perpetrated by past authors. 



The next reference to Cyclostoma appears under the 

 authorship of Draparnaud, 1801 (Tabl. Moll. Terr. Fluv. 

 France, pp. 37, 38), who employed for his type the shell so- 

 familiar to all students of conchology, viz. the Nerita elegans 



