1884.] 'lightning' and 'porcupine' expeditions. 115 



oval : outer Up thin, smooth within : inner lip somewhat reflected 

 and thickened on the lower part of the pillar, which is imperforate. 

 L. 0075, B. 0-045. 



' Porcupine ' Exp. 1870 : Atl. St. Tangier B. Two specimens. 



Differs from R. punctura in being more slender or narrower and 

 of an oblong shape ; and the sculpture is not reticulated. 



v 12. Rissoa subsoluta, Aradas. (Plate IX. fig. 3.) 



R. subsoluta, Ar. Mem. di Make. Sic. iii. (1847), p. 21. 



'Porcupine ' Exp. 1870 : Atl. St. 1, 3, 9, 13, 14, 16, 24, 26. 



Distribution. Bay of Biscay (' Travailleur ' Exp. 1880) ! ; Medi- 

 terranean (Nares, Spratt, Monterosato) ; 108-310 fms. 



Fossil. Pliocene : Messina (Seguenza) ! 



In some specimens (as described by Aradas) the longitudinal 

 stria? partially disappear, or are entirely wanting, on the last and 

 penultimate whorls. 



The sculpture of this pretty little shell is much finer than that of 

 the next species (R. testes), and the spire is more bluntly pointed. 

 I described it in my paper on Mediterranean Mollusca (Ann. & Mag. 

 N. H. 1870) as the variety obtusa of that species under the name of 

 R. abyssicola. At one time I considered the species named and de- 

 scribed by Aradas the same as that which I now propose to call 

 deliciosa, and which will be described and figured in this paper ; 

 but I have since been enabled to rectify the mistake by the exami- 

 nation of a typical specimen of R. subsoluta, which I received from 

 the late Professor of Catania. The present species is R. elegan- 

 tissima of Seguenza. 



„ 13. Rissoa test;e, Aradas & Maggiore. (Plate IX. fig. 4.) 



R. testce, Ar. & Magg. Cat. rag. Catania, 1844, p. 207. 



' Porcupine ' Exp. 1869 : St. 2, 3, 10, 16. 1870 : Atl. 3a, Vigo 

 B., Setubal B., 22, 24, off C. Sagres, 26-34, 36 ; Med. 40, 41, 45, 

 Cartagena B., 50, Benzert Road, Adventure Bank, off Rmaldo's 

 Chair. In most of the first-named Stations the variety abyssicola 

 is the prevalent form. That variety is more oval, and has a rather 

 more oblique spire and finer sculpture than the typical form ; it is 

 described and figured in the ' British Mollusca,' vol. iii. p. 86, 

 pi. Iviii. f. 1, 2, and (animal) pi. JJ. f. 3, and in " British Con- 

 chology,' vol. iv. p. 19, and v. p. 207, pi- lxvi. f. 9. 



Distribution. Typical form : Atlantic coasts of France and Spain 

 to the Mediterranean and Adriatic ; 11-640 fms. Var. abyssicola: 

 Arctic, Norway to Mizen Head, Co. Cork ; 30-300 fms. 



Fossil. Typ. Pliocene : Italy. Var. abyssicola. Post-tertiary : 

 Christiania district (Crosskey and Robertson). 



In the above-cited paper on Mediterranean Mollusca I named the 

 present species the variety conformis of R. abyssicola, not being 

 then aware of the publication by Aradas and Maggiore. I after- 

 wards received from the lamented Professor Aradas typical specimens 

 of R. testce, which not only confirmed my opinion that it was the 



8* 



