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NOMENCLATURE OF BRITISH LITTORINID^. 



By R. WiNCKWOKTH. 



Read 7th April, 1922. 



The species formerly included under Littorina seem suflSciently 

 distinct iu methods of reproduction to merit separation into distinct 

 genera. It has long been known that L. littorea has pelagic egg 

 capsules and passes through a free veliger stage, while L. rudis is 

 viviparous, and L. littoralis, like the species of Lacmia, deposits eggs 

 in ootheca on seaweeds. 



Dr. Dall and others in recent years have assumed the type of 

 Littorina, Ferussac, to be littoralis, L., presumably following Rang's 

 selection in 1829. But this species is not included in Ferussac's 

 original description, which is found in the Tableau, 1822, p. xxxiv : — 



" Paludina . . . 5e S. G. Littorine, Littorina, Feruss. ; Turbo, 

 Lin. ; Trochus, Adanson ; Kruck, Ocken." 



Of these three references the first. Turbo, L., is too wide to give 

 any indication ; we may note, however, that it includes littoreus, 

 neritoides, and obtusatus, but not littoralis, which is described under 

 Nerita, L. The second, Trochus, Adanson, pi. xii, includes four 

 species : Marnat = Turbo punctatus, Gm., allied to saxatilis, Olivi ; 

 Boson = Turbo muricatus, L., a Tectarius ; Daki and Rifet, included 

 in Gmelin's Turbo afer, and both, I think, indeterminate. The last 

 reference is to Oken, Lehrbuch Naturg. iii, 1, 1815, p. 257, where we 

 find : 4 Gattung, Kruck ; 1 Turbo littoreus ; 2 Turbo punctatus. 



Thus the species available for selection as type are punctatus, 

 muricatus, afer, and littoreus ; and the selection is made by Blainville, 

 1828, in Diet. Sci. Nat., Ivi, p. 98, where he refers to " le genre 

 Littorine ayant pour type le T. littoreus ". So, too, Deshayes, 

 1843, in Lamarck, Hist. Anim. s. Vert., ed. 2, ix, p. 198, note; 

 and, again. Gray in Proc. Zool. Soc, 1847, definitely designate 

 littoreus as type of Littorina. Algaroda, Dall, 1918, with the same 

 type is an absolute synonym. 



For the littoralis group. Brown's name Neritoides, in Illust. Brit. 

 Conch., 1827, pi. xliii, with sole species littoralis, is available. The 

 previous Neritoides, Meuschen, 1779, does not invalidate Brown's 

 name, since it occurs in an article in Naturforscher, xiii, p. 78, 

 in which the author has not applied the principles of binary 

 nomenclature (Rule 256). 



L. neritoides is usually referred to the genus Melarhapke, Menke, 

 which occurs in synonymy in his Synopsis Methodica Molluscorum, 

 1828, p. 23 : " Paludina glabrata, Zgl. {Turbo caerulescens, Lam., 

 T. rupestris, Chabr., Melarhapke glabrata, Mhlfld.)." Paludina 

 glabrata, Zgl., is described by C. Pfeifier, 1828, in Naturg. Deutsch. 

 Moll., iii, p. 46, and from the figure must be Turbo neritoides, L. ; 

 these names in the second edition of Menke's Synopsis, 1830, are all 



