2 



2 THE VOYAGE OF H.M.S. CHALLENGER. 



the generic terms Oscanius 1 and Cleanthus to the first group of Montagu's Lamellarice 

 (Lamellaria membranacea), but regarded these only as subgeneric divisions within 

 Cuvier's genus Pleurobranchus. For the remaining group, here under discussion, he 

 rejected the misleading designation Sigaretus, and formed the title Marsenia. As the type 

 of the new genus he proposed Bulla haliotoidea, Mtg., Test. Brit. (= Lamellaria haliotoidea, 

 Linn. Tr.), but, in order to obviate ambiguity, changed the name to Marsenia producta. 



Somewhat later (1824) Blainville described a form, from the Isle de France, quite 

 different from, but yet allied to the "Sigarets" of Cuvier, the Lamellaria (p.p.) of 

 Montagu, and the Marsenice of Leach, and established for it the genus Coriocella? 

 This, however, turned out to be a Marseniad with a very thin shell, which had fallen 

 off the specimen described by Blainville, as was indeed soon remarked both by Gray 4 

 and Cuvier. 5 Blainville wished to transfer the name Sigaretus to related forms with 

 distinctly developed internal shell, but of the two species which he included in this group, 

 only one bears the characters of the genus, while the other (Sigaretus haliotoideus, 

 Martini, vol. i. Taf. 16, Figs. 151-154) belongs to the genus Stomatia, Hill (Cryptostoma, 

 Blainville). In the article "Sigaret" in the 49th volume of the Diet. Sci. Nat., which 

 appeared a few years later, the statement of the generic characters is unaltered, while the 

 number of included species is increased to eight, of which, however, six at least are forms 

 of Stomatia. (Here Blainville also seemed much inclined to regard the Helix perspicua 

 of Linne as a Pleurobranchus.) Some years later (1830) Menke adopted the recently 

 established designation Cryptostoma, using it as a synonym for " Sigaretus, Lamarck, 

 Sow." (!), and proposed in verbal contrast the name Cryptothyra e for Blainville's Coriocella;; 

 while Swainson 7 afterwards suggested the term Chelinotus. 



The group which had gathered round the Helix perspicua of Linnd had thus received 

 sis names: "Sigarets" from Cuvier (1799.), Lamellarice from Montagu (1811), MarsenicB 

 from Leach (1819), Coriocellce from Blainville, Cryptothyra from Menke (1830), and 

 Chelinoti from Swainson (1840). This had, so far, its explanation in the imperfection 

 and insufficiency of Cuvier's first investigation and descriptions, which made it almost 

 impossible for other investigators to know what form Cuvier had before him. Nearly all 

 are agreed, at least, in rejecting the originally indefensible and misleading name Sigaret, 

 Sigaretus. Montagu's title Lamellaria, if used to denote the first of Montagu's species, 

 that is, a form of Pleurobranchus, would become identical with the Oscanius or Cleanthus 



1 Nee Oscana, Bosc (a parasitic Crustacean). 



2 Leach, Synopsis of Brit. Moll., 1820 (teste Gray, Ann. and Mag. Nat. Hist, Oct. 1847, voL xx.) ; see 

 Oken, Ms, 1823, Bd. ii. p. 460 (Mus. Paris).— Leach, MolL Brit. Synopsis (ed. Gray), 1852, p. 26. 



3 Diet. Sci. Nat., 1824, t. xxxii. p. 259.— Man. de Malacol., 1825, p. 466. 



4 Gray, Spicilegia Zoolog., 1828, pt. 1, p. 4 ; cf. also Gray, Proc. ZooL Soc. Lond., 1847, p. 143. 



5 Cuvier, Regne animal (ed. 2), 1830, vol. iii. p. 90. 

 e Menke, Synopsis (ed. 2), 1830, p. 87. 



7 Swainson, A Treatise on Malacology, 1840, pp. 234, 355. 



