1884.] 'lightning' AND ' PORCUPINk' EXPEDITIONS. 127 



ranean, Adriatic, and var. Madeira {Watson) ; 0-80 fms. Bay of 

 Biscay (' Travailleur ' Exp. 1881); 640 fms., most probably drifted. 



Fossil. Pliocene : Monte Mario. Post-tertiary : Portrush and 

 Leghorn. 



I would refer to ' British Coachology ' for the synonyms of this 

 rather variable species. And I am inclined to add to the list my 

 B. pieta, as well as R. granulum of Philippi, B. gulvagni of Aradas, 

 R. depicta of Manzoni, R. maculata and R. concinna of Monterosato, 

 R. tenuiplicata of Segueuza, and R. (smula of Granata. 



I regret to differ so much from some continental conchologists with 

 respect to the comparative value of certain characters whieli have 

 induced tbem to make so many species out of what I believe to be 

 mere varieties ; but I do not attach so great an importance as they 

 evidently do to the difference of specimens, whicli are abundant, widely 

 distributed, and consequently variable. However, they may have as 

 much right to regard these as distinct species as I have to* consider 

 them varieties ; and it is not very important whether such forms are 

 called by one name or the other. 



Some specimens have a reticulated sculpture in consequence of the 

 spiral striae covering all the surface of the shell, and being crossed 

 by close-set longitudinal strise. The texture of these specimens is 

 thicker and stronger than usual. 



i/^4l. RissoA ciNGiLLUs, Moutagu. 



Turbo cingillus, Mont. Test. Br, p. 328, t. 12. f. 7. 



R. cingillus, B. C. iv. p. 48 ; v. p. 208, pi. Ixviii. f. 9. 



' Porcupine ' Exp. 1869 : St. Donegal B. 



Distribution. Iceland {&s Helix pella of Linne) ? Norway, Sweden, 

 Denmark, Faroe and British Isles, northern and western coasts of 

 France and Spain, Mediterranean ; 0-20 fms. 



Fossil. Post-tertiary : Scotland, Ireland, and Tuscany. 



Several old synonyms ; but if the existence of this species in 

 Iceland were established, instead of doubtfully depending on the 

 authority of Zoega, one of Linne's pupils, the specific name ought to 

 be pella, although by no means appropriate. 



42. RissoA ASTURiANA, Fischer. 



Plagiostila asturiana, Fisch. in ' Les Eouds de la Mer ' i. n .50 

 pi. 11. f. 5. ' 1 ' 



'Porcupine' Exp. 1870: Med. St. Gibraltar Bay. 



Distribution. Gijon and Vigo Bay {de Folin) ; 10-18 fms. 



I cannot separate this species, however peculiar and interesting, 

 from Rissoa by any definite character. In comparison with R. lactea 

 the shape is similar ; the papillary apex, the disproportionately 

 large size of the last whorl, the obliquity of the axis or pillar, the 

 semilunar form of the aperture or mouth, and the thickened peri- 

 stome are the same in each of those species. The chief difiference 

 consists in the present species being devoid of sculpture. Perhaps 

 both species might constitute another section of Rissoa. 



