401 

 THE VALIDITY OF THE l^AUE^—TESTACELLA 

 MAUGEI PER. AND r. HALIOTIDEA DRAP. 



HUGH WATSON, M.A. 



Messrs. A. S. Kennard and B. B. Woodwai-d have recently 

 maintained {Proc. Malac. Soc, Vol. XIV., 1920, pp. 77-80) 

 that the specific names usually applied to two of the three 

 British species of carnivorous slugs are invalid, and the 

 name Testacella maugei Fer. ought to be replaced by T. 

 haliotoides Lam., and that of T. haliotidea Drap. by T . eiiropcB'a 

 Roissy. It is evident that these changes will introduce great 

 confusion into our nomenclature, for the names T. maugei 

 Fer. and T. haliotidea Drap. have both been employed for 

 more than a hundred years, and to change them, as suggested, 

 will certainly be troublesome, especially in view of the simi- 

 larity between the names T . haliotidea Drap. and T . haliotoides 

 Lam. The following notes show, however, that even the 

 priority purist should hesitate before accepting either of these 

 changes. 



Let us first consider the case of Testacella maugei Fer. 

 The earliest description of the genus Testacella was pub- 

 lished in 1 80 1 by Lamarck {Syst. Anim. s. Vert., p. 96), who 

 adopted the generic name proposed by Cuvier in the previous 

 year {Lecons d'Anat. Comp., Vol. t., table V.), and cited 

 Favanne, pi. 76, Limaces a coquilles.' Lamarck also gave 

 as an example of this genus, ' Testacella haliotoides n. ex D. 

 M auger, ex ins. TeneriffcB.' Now Jac. de Favanne, on pi. 

 LXXVI. of the third edition of Desallier d'Argenville's ' Con- 

 chyliologie,' depicts three species of ' Limaces a coquilles,' 

 which he and his son describe on p. 429 of Vol. I. of the same 

 work. They say that they owe the first species to M. de La 

 F^aillo, of La Rochelle, who had shown them the animal itself. 

 The source of the second species is not stated. The third, of 

 which the authors had apparently only seen a figure, is sup- 

 posed to be a native of the Maldive Islands. These last two 

 species were named Testacella costata and T. cornina respect- 

 ively by Bosc {Hist. Nat. Coquilles, Vol. III., 1802, p. 240) ; 

 but in 1819 Ferussac placed them in a separate genus, which 

 he named Plectrophonis {Hist. Nat. Moll., Vol. II.,' pp. 

 84-88). Their peculiar characters are probably partly 

 mythical. The first species of Favanne, however, is evidently 

 founded on the specimen preserved in spirit, which Ferussac 

 states was sent to Favanne in 1774 by de La Faille, who at- 

 tributed the slug's discovery to Guillemeau, a physician at 

 Niort, twenty-five miles inland from La Rochelle. This 

 species was a true Testacella, Ferussac stating, on the testimony 



1921 Dec. 1 



2D 



