MARSHALL : ADDITIONS TO BRITISH CON'CHOLOGY. I99 



var. striata Penn. — Off Cork Harbour (Wotton) ! off Aberdeen 

 (Simpson) ! North Rona, 45f ; Doggerbank, 3of. 



var. pelagica King. — Aberdeenshire (Simpson) ! off Unst 

 (Coulson) ; Shetkands (coll. MacAndrew). In this variety the kast 

 whorl is smaller and narrower proportionally, hardly projecting beyond 

 the penultimate, and in British specimens the longitudinal ribs are 

 evanescent or wholly wanting. My largest examples exceed 6iin. in 

 length. It occurs in Norway, but of a smaller size and strongly ribbed. 



var. zetlandica Jeff. — Gwyn Jeffreys has described this variety as 

 "destitute of ribs," whereas he figures it with rather prominent ones, 

 and this has given rise to some doubts as to whether the var. zetlandica 

 is ribbed or not, especially as he compares it with B. JmnipJireysiaiium^ 

 which is ribless, while this is rendered more confusing by its living on 

 the same fishing-grounds with a dwarf and thin form of \-Ar. Jlexuosa, 

 which is ribbed, in the Orkneys and Shetlands. But the real truth is, 

 that the presence or absence of ribs is not a criterion of this variety, its 

 only permanent characters being that it is dwarfed and thin. It is 

 almost as variable as the type, and really runs into many forms when 

 collected from different parts of the Shetland seas. It is seldom 

 without traces of longitudinal ribs, especially on the upper whorls, and 

 there is considerable variation in the size, comparative length of spire, 

 and degree of sculpture. To give an idea of its extreme variability, 

 I may say that I have specimens of it corresponding not only to the 

 ribbed type, but to the var. striata^ the \^.\. flexuosa, \\\q \^r. pe/agtca, 

 and the var. acuminata. In rare instances it is as finely striated as B. 

 hnniphreysiammi, while on the other hand I have examples which are 

 as much ribbed as any typical shell. Nor is Gwyn Jeffreys' white 

 specimen at all singular ; 1 have a series of them. 



Some large specimens of the zetlandica-striata form, which may be 

 ascribed to either variety, have been trawled off Fair Isle, midway 

 between the Orkneys and Shetlands. They are deceptive examples, 

 and much resemble B. finniarkiauniit, from Upper Norway, etc., 

 a species having several synonyms, but which perhaps is only an 

 extreme form of B. grcenlandiciini. Another very pretty form from 

 the East Shetlands, 6o-9of., is white, very finely striated, extremely 

 thin, with a cinereous, silky, deciduous epidermis, a form which 

 also occurs at Vardo, Finmark, in ioo-i5of. ; this is B. schneideri 

 Verk. The same form was also trawled off S.W. Ireland, in 55f, by 

 the Rev. W. S. Green, and off the south and west of Ireland, in 

 90-i8of., by the 'Porcupine.' B. parvulnni Verk. is different from this, 

 and is a white variety of B. grcenlandicum, its specific identity being 

 indicated by the size, contour, spire, embryo, and micro sculpture. 

 Jeffreys' figure is much too large, and the spire too long for var. 



