120 DR. GWYN JEFFREYS ON THE MOLLUSCA OF THE [Feb. 19, 



24. RissoA NANA, Philippi. 



B. pusilla. Ph. Moll. Sic. i. p. 154, t. x. f. 13. 



jB. nana, Id. op. cit. ii. p. 127. 



'Porcupine' Exp. 18/0 : Med. St. 55, Adventure Bank. 



Distribution. C/Oasts of Western France, the Mediterranean and 

 Adriatic ; 30-777 fms. 



Fossil. Miocene : Madeira. Pliocene : Monte Mario and Calabria. 

 Post-tertiary : Rhodes. 



The reason given by Philippi for changing the name which he 

 originally proposed, viz. because Brocchi had previously given the 

 name pusillus to a species of Turbo, was not satisfactory, inasmuch 

 as Brocchi's shell belonged to Rissoina and not to Rissoa. This I 

 have ascertained by an examination of Brocchi's specimens. But 

 the change has been sanctioned and adopted by modern coii- 

 chologists. 



Not jB. nana of Grateloup, which is a Miocene species of the 

 Bordeaux Basin, nor It. nana (Partsch), Homes, from the Vienna 

 Basin, both names being subsequent in date to that of Philippi. I 

 greatly doubt the identification of the present species with M. dolium 

 of Nyst, which name was substituted by him for R. pusilla of Marcel 

 de Serres, also a fossil of the Bordeaux Basin. Possibly our species 

 may be the R. pulchra of Forbes ; but the size which he gives (one 

 tenth of an inch) is far too great. Unfortunately the ^gean shells 

 were dispersed, and many of them lost to science ; his descriptions, 

 or rather notices, were too short and insufficient for the exact com- 

 parison of his species, and very few of them were figured. 



I 25. Rissoa turricula \ Jeffreys. (Plate IX. fig. 6.) 



Shell turreted, thin, semitransparent, and somewhat glossy : 

 sculpture, 20-25 slight and gently curved longitudinal ribs on the 

 last whorl, and nearly as many, but finer, on the next whorl ; the 

 remainder of the shell is smooth ; there are no spiral strife or other 

 markings : colour whitish : spire pointed : whorls 4, swollen, 

 gradually increasing in size ; apex slightly twisted on one side : 

 suture deeply excavated : mouth roundish : outer lip sharp ; inside 

 smooth : inner lip reflected on the lower part of the pillar, behind 

 which is a small chink. L. 0-05. B. 0-035. 



' Porcupine ' Exp. 1870: Atl. St. 3. Two specimens, not in good 

 condition. 



I propose this species with some hesitation, because the specimens 

 have the appearance of being decorticated, like casts of a fossil shell ; 

 but I cannot identify them with any known species. 



V 26. Rissoa inconspicua, Alder. 



R. inconspicua, Aid. in Ann. & Mag. N. H. xiii. p. 223, pi. viii. 

 f. 6, 7 : B. C. iv. p. 26 ; v. p. 207, pi. ixvii. f. 5. 



' Porcupine ' Exp. 1869 : St. Donegal, B. 1870 : Atl. Vigo B,, 24, 

 26-30, 35, Tangier B. : Med. 50, Adventure Bank. 



* A little bower. 



