522 TEST ACE A ATLANTICA. 



regarded by Reibisch, who cited it under the varietal name of 

 ' ribeirensis.^ Dohrn however was inclined to treat it as truly 

 distinct, — ' the dark horn-colour and smooth surface ' being, as 

 he thought, sufficient to separate it altogether from the L. 

 auricularia ; and he added that the title which was proposed 

 by Eeibisch for the variety might conveniently be carried on 

 for the species ; and it was consequently quoted by him as the 

 ' L. ribeirensis, Keib.' Still, Morelet, who has paid consider- 

 able attention to the members of the present genus, does not 

 appear to share Dohrn's opinion on this point, for he enters 

 it into his more recently published list as the auricularia ; and 

 I am disposed to act on his conclusion, and to treat it, as 

 Eeibisch did, as a mere local state, or modification, of that 

 species. 



Limnsea ovata. 



Limneus ovatus [var.], Drap.^ Hist. Nat. des Moll. 50 (1805) 

 Limngeus ovatus, v. Stiibeli, Reib., Cat. (1865) 

 Limnsea sordulenta, Dohrn [vix Morel.\ Mai. Blcitt. xvi. 14 



(1869) 

 „ ovata. Morel..) Journ. de Conch, xiii. 239 (1873) 



Habitat S. Antao, S. Nicolao, S. lago, et Brava : hinc inde 

 in aquis. 



By Dohrn this Limncea was taken in S. Antao, S. Nicolao, 

 and S. lago, and by myself in S. lago and Brava. It differs a 

 little from the common European form of the L. ovata, — ' the 

 glossy surface of the shell' being particularly alluded to by 

 Dohrn, who regarded the species not only as distinct but iden- 

 tical with the L. sordulenta, Morelet, from Angola. Reibisch, 

 on the other hand, treated it as a mere phasis (a ' var. Stiibeli ') 

 of the ovata, — a conclusion which Morelet seems inclined to 

 accept. ' Je partage,' says the latter, ' I'avis de M. Reibisch 

 qui considere cette forme une simple variete de Yovata : les 

 SLijets que j'ai sous les yeux ne me laissent aucun doute a cet 

 egard. M. Dohrn a cru reconnaitre, dans ceux qu'il a recueillis 

 lui-meme sur les lieux, la L. sordulenta d' Angola, ce qu'il faut 

 attribuer, sans doute, a I'insuffisance de la description et de la 

 figure que j'en ai donnees. Tout en conservant une grande 

 analogic avec notre espece d'Europe, la L. sordulenta est bien 

 moins ventrue que Vovata ; son ouverture, par suite, est moins 

 dilatee, et la spire est aussi moins aigue. J'ajouterai qu'aucun 

 Mollusque de nos climats n'a ete rencontre jusqu'ici sur la cote 

 de Guinee.' 



