NEWTON: ON rOLUTILITHES. 103 



Swainson's V. pertusa was, however, never referred to by Edwards in 

 his monograph on the Eocene Mollusca, and it is possible that he was 

 not familiar with the " Zoological Illustrations " for 1831 ; in any case 

 it is quite certain that the older name must be acknowledged, whilst 

 V. humerosa must be relegated to synonymy. 



Since Swainson's description appeared this shell has only been 

 once systematically noticed in literature, and that was by Deshayes 

 (see Deshayes and Milne Edwards' edition of Lamarck's Hist. Nat. 

 Anim. sans Vert., 1844, vol. x, p. 430), who described it as Voluta 

 pertusa, Swainson, and localised it as a " Fossile de Courtagnon." No 

 locality is given in Swainson's original text for this species, so that 

 the statement as to "Courtagnon" was made without authority and 

 is absolutely incorrect, the shell having been obtained from Barton 

 and not from the French Eocenes. In much more modern times 

 M. Cossmann has recognized that Voluta humerosa of Edwards 

 should be associated with Gray's genus L^Jria (see Cossmann's 

 "Essais de Paleoconchologie Comparee," 1899, 3rd livr., p.- 114), 

 although the evidence is greatly in favour of its being a true 

 Volutilithes, the protoconch appearing to have the same elements of 

 structure as characterize Lamarck's muricma. 



The genera and species involved in this discussion may be tabulated 

 as under, the distribution in time being taken from Cossmann's " Essais " 

 before quoted : — 



YoLTJTA, Linnaeus, emend. Lamarck. 



Linn., Systema Nature, 1758, 10th ed., p. 729 ; Lamarck, Mem. Soc. Hist. Nat. 

 Paris, 1799, p. 70. 



Synonym. — Volutolyria, H. Crosse, Journ. Conchyliologie, 1877, 

 vol. XXV, p. 99. 



Type. — Voluta musica, Linnaeus. A fossil example= Voluta musical is, 

 Lamarck. 



Distribution in time. — Tertiary (Eocene) to Ilecent. 



VoLUTILITHKS, SwaiuSOU. 

 Zoological Illustrations, 1831, ser. ii, vol. ii, pi. liii, fig. 2. 



Synonym. — Uopsephcea, P. Fischer, Manuel Conchyliologie, 1883, 

 p. 607. 



2ype. — Voluta vmricina, Lamarck. Another example is Volutilithes 

 pertusa, Swainson. 



Distribution in time. — Cretaceous (Turonian) to Tertiary (Eocene). 



VoLTJTOsPiNA, R. Bullen Newton, nom. mut. 



Synonyms. — Plejona, Bolten,;?«rs, Museum Boltenianum, 1798, p. 59; 

 Volutilithes, Swainson, A Treatise on Malacology, 1840, p. 318, 71071 

 Swainson, 1831. 



Type. — Cojius spitwsus, Linnaeus. 



Distributio7i m ti77ie. — Cretaceous (Turonian) to Kecent {=:Fhilip- 

 pianu, Dall). 



