TRICHOTROPIS KROYERI. 429 



below the suture; suture deep and sub-canaliculate; ridges generally spinous, 

 beaded in the recent shell or when the epidermis is present ; mouth large, nan-owed 

 below; outer lip thin, expanded, scalloped by the ribs; inner lip reflected on the 

 pillar with a rather long sub-umbilical chink behind it; canal short, pointed, 

 narrow. 



Dimensions. — L. 16 mm. B. 9 mm. 



Distribution. — Recent : British coasts, northern and local, from the Dogger 

 Bank to the Shetlands, west of Scotland, Irish Sea, Lough Strangford, co. Galway. 



Circumpolar : north-west coast of Norway, Hammerfest, Lofoten Islands, 

 Faroes, Greenland, Labrador, New England coast, Behring Sea, Siberia, Nova 

 Zembla, Spitsbergen, Kara Sea. 



Fossil : Coralline Crag : Gedgrave, Sutton. Newbournian : 

 Waldringfield. Butleyan : Butley. Iceland Crag. Isle of Man (Kendall), Wexford. 



Pleistocene : Bridlington, Macclesfield, Moel Tryfaen, Garvel park, Bute. 



Ficarazzi. typ-i^a-beds, Christiania. . Trondhjem (0yen). Siberia, Canada, 

 Labrador. 



Remarks. — This species, the general range of which both as living and fossil is 

 arctic and circumpolar, was one of the few and rare northern forms occurring in 

 the Coralline Crag, whose molluscan fauna as a whole points to the existence at 

 that period of comparatively warm conditions. A single characteristic specimen 

 of it, however, was found by Brugnone in the Sicilian Pleistocene of Ficarazzi, 

 which has recently been figured by M. Gignoux (pp. cit.). It seems to have been 

 very rare in the Anglo-Belgian basin during the Pliocene epoch, having been 

 reported from two Red Crag localities only — Waldringfield and Butley. This may 

 be due perhaps to its having been more or less a deep-sea species. Mr. Friele 

 dredged it during the North Atlantic Expedition at various depths to about 

 400 fathoms. 



One of the specimens here figured is from the Coralline Crag and belongs to 

 the Sedgwick Museum, the other, which is a larger and stronger form, comes from 

 Ipswich and was found at Waldringfield. With them I give for comparison a 

 recent shell from Tromso. 



Trichotropis Kroyeri, R. A. Philippi. Plate XLIV, fig. 35. 



1845. Trichotropis Kroyeri, Philippi, Zeitschr. f. Malakoz., vol. v, p. 175. 



1849. Cancellaria (?) arrttca, Middendorff, Beitr. Make. Eoss., pt. ii ; Mem. Aead. Imp. Sci. St. 



Petersb. [6], vol. vi, p. 441, pi. ix, figs. 11, 12, 15. 

 1851. Trichotropis dolium, Petit, Journ. de Conch., vol. ii, p. 20, pi. i, fig. 4. 

 1869. Trichotropis (Iphinoe) Kroyeri, Morch, Ann. Soc. Roy. Malac. Belg., vol. iv (Memoires), p. 14, 



no. 9. 

 1872. Trichotropis arctica ?, Dawson, Canadian Nat. (n.s.), vol. vi, p. 395. 



