290 PLIOCENE MOLLUSCA. 



1888-93. Pleurofoma pyramidalis, A. Bell, Rep. Brit. Assoc. (Bath), p. 135, 1888 ; Proe. Eoy. Phys. 



Soc. Ediub., vol. xii, p. 22, 18'.>3. 

 1905. Bela j;///-«;H/(Za//s, Kobelt, Icou. scliixlentrag. eui'op. Meerescoucli., vol. iii, p. 259, pi. Ixxxiii, 



fig. 23. 

 1910. Bela pyramidalis, Odhner, Kongl. Svensk. Vet.-Akad. Haiidl. Stockholm, vol. vii, p. 12. 



Specijic Characters. — Shell elongato-fusiform ; whorls 7 — 8, convex, not 

 distinctly carinate, the last about half the total length ; ornamented by from 

 12 — 16 flexuous and oblique longitudinal costae, sometimes strong and prominent, 

 at other times nearly obsolete, generally disappearing on the body-whorl, and by 

 fine but distinct spiral ridges; spire attenuate, regularly diminishing in size; 

 suture deep ; mouth pyriform, angulate above, short and fairly wide ; outer lip 

 gently curved, passing into a short and open canal ; columella flexuous. 



Dimensions. — L. 15 — 20 mm. B. G — 7'5 mm. 



Distribution. — Recent : northern and Arctic seas, not known on the Norweo-ian 

 coast to the south of Lofoten. Greenland, east coast of North America to Cape 

 Cod, Jan Mayen, Iceland, the Faroes, Murman coast. White Sea, Spitzbergen, 

 Barents Sea, Nova Zembla, Kara Sea, Arctic shores of Siberia. 



Fossil : Newbournian Crag : Waldringfield, Foxhall, Felixstowe. 

 Butleyan : Boyton, Butley, Hollesley. 



Pleistocene : Area-clay, Tapes-banks, Christiania region (Br0gger), Trondhjem 

 (0yen), Udde valla, Murman coast, Siberia, Labrador (Friele). 



BemarJcs. — Of this species two or three well-marked varieties occur in the 

 Crag, one or more of them being found at all horizons from the Red to the 

 Icenian. 



The specimens now figured, which correspond most nearly with Prof. Sars' 

 type-form, are from Waldringfield and Butley, but I have not found any of them 

 at Oakley. 



Of the shorter form, var. semij)licata, of Sars, I have two from the latter place ; 

 it does not appear to be very common elsewhere. The ecostate variety, var. 

 Ixvinscnla, I only know from the Icenian deposits and as a Pleistocene fossil; it 

 might be interesting to ascertain whether such a zonal classification can be 

 confirmed by further research. 



Var. semiplicata, G. 0. Sars. Plate XXIX, figs. 84, 35 ; Plate XXXII, figs. 5, 6. 



1842. Defrancia Vahlii (Beck), MOller, lud. Moll. Groenl., p. 13. 



1878. Bela pyramidalis, var. semiplicata, G. O. Sars, Moll. Reg. Arct. Norv., p. 222, pi. xvi, fig. 4. 



1886. Bela pyramidalis, var. semiplicata, Friele, Norske Nordh. Exped. (MoUusca), pt. ii, p. 22. 



1887. Bela pyramidalis, var. semiplicata, Aurivillius, Vega Exped., Vet. lakt., vol. iv, p. 349. 

 1899. Bela pyramidalis, var. Vahlii, Posselt, Medd. om Gronl., vol. xxiii, p. 161. 



1905. Bela pyramidalis, var. semipilicata, Kobelt, Icon, sclialentrag. europ. Meei'escouch., vol. iii, 

 p. 259, pi. Ixxxiii, fig. 22. 



