105 



ON THE GENERIC NAME TO BE APPLIED TO THE VENUS 

 ISLANDICA, LINN. 



By E. A. Sjiixn, I.S.O. 



Read 12th April, 1912. 



A CONSIDERABLE aiuount of discussion has already taken place 

 concerning the generic name wliich should be applied to the well- 

 known Cyprina Islandica, the Venus Islandica ot Linnoeus, and the 

 latest writer upon the subject, Dr. W. H. Dall/ has assigned this shell 

 to the genus " Cyclas (Bruguiere), Link". 



Kow Bruguiere's plates in the Encyclofklie Methodique (pis. 301, 

 302) with the word Cyclas at the top (he never published a description) 

 do not include a figure of Cyprina Islandica, and the figures \a, \b, on 

 plate 301, referred to by Dall as representing that species are very 

 good illustrations of some form of the genus Batissa. 



Dr. Dall's mistake may have arisen from the fact that in the 

 explanation of the plates by Bory de St. Vincent,- the name Cyprina 

 Islandica,'^ Lamk., is given (erroneously) to the two figures quoted 

 above. But of this I feel certain, that Dr. Dall did not actually 

 see the figures, for he is too good a conchologist to have regarded 

 them as representing the above-named species. 



The genera figured on Bruguiere's two plates are Batissa, Corhicula, 

 Cyrena, and Sphcerium, as now generally understood, and perhaps 

 Astarte, but not Cyprina. Bruguiere's genus Cyclas has therefore 

 nothing to do with Cyprina. 



Link, in 1807,* placed the northern shell in " Cyclas (Lam.)", it 

 being the only species he mentions. But this name cannot be used, 

 as it had already been employed by Lamarck in 1799^ in a different 

 sense for the Tellina cornea., Linn., now known as Sphcerium corneam. 

 The figure in the Encyclopedie Meth. (pi. 301, figs. 1^, \h) upon 

 which Dall based the genus " Cyc/rts (Bruguiere), Link", does not, 

 as already observed, represent the Cyprina Islandica.'^ The form of 

 the outline is quite different, and the erosion of the apex and the 

 dentition at once indicate a species of the genus Batissa. Observe 

 the crenulated lateral teeth in fig. \h, pl feature non-existent in 

 Cyprina Islandica. 



^ Trans. Wagner Free Inst. Sci. Pbilacl., vol. iii, pt. vi, p. 1500, 1903. 



" Tabl. Eucycl. Method. Vers. Moll., etc., p. 156. 



■* Also quoted by Lamarck as Cyclas Islandica, Ann. Mus. Nat. Hist. Paris, 

 vol. vii, p. 420, 1806. 



■* Nat. Sammlung, Kostock, 1807, p. 150. 



5 Mem. Soc. Hist. Nat. Paris, 1799, p. 84. 



*' All the following authors refer to this figure as representing the shell now 

 known as Batissa violacea: Desbayes (Eneycl. Meth. Vers., vol. ii, 

 p. 49, 1830) under Cyrena violacea, Lamk. ; id. (Cat. Conch. Brit. Mus., 

 pt. ii, p. 238) under Batissa violacea (Lamk.) ; Philippi (Conchylien, 

 vol. iii, p. 108) under Cyrena violacea, Lamk. ; Prime (Amer. Journ. 

 Conch., vol. vii, p. 140) under Batissa violacea (Lamk.); Clessin (Conch. 

 Cab., p. 208) under B. violacea. 



