558 PLIOCENE MOLLUSCA. 



adopted in preference. It is not a common Crag shell, but has been obtained from 

 the Coi'alline Crag of Boyton and Sutton, from the AValtonian of Little Oakley by 

 myself, and from one of the Dutch borings by Dr. Tesch. 



Genus ACIRSA, Morch, 1857. 

 Acirsa Eschrichti (Holboll). Plate XLIX, figs. 6, 7. 



1838. Scalaria (Acirsa) horealis, Beck iu LTell, Phil. Traus. [1], p. 37, pi. ii, fig. 11. 



1842. Scalaria Eschrichti, Holboll in MoUer, lud. Moll. Groenl, p. 10. 



1858. Scala (Acirsa) Eschrichti, H. and A. Adams, Greu. Rec. Moll., vol. ii, p. 621. 



1863 — 77. Mesalia horealis, Jeffreys, Rep. Brit. Assoc. (Newcastle), p. 78, 1868; Acirsa Eschrichti, 



Proc. Roy. Soc, vol. xxv, no. 173, pp. 193, 194., 1876 ; Aun. Mag. Nat. Hist. [4], vol. xix, p. 241, 



1877. 

 1872. Acirsa Eschrichti, Dawson, Canad. Nat. [n.s.], vol. vi, p. 394. 

 1876. Scala {Acirsa) Eschrichti, Morcli iu Rink. Dan. G-roenl , p. 436. 

 1890. Acirsa horealis, A. Bell, Rep. Brit. Assoc. (Leeds), p. 415. 

 1898. Scalaria (Acirsa) horealis, Posselt, MeJd. om Groul., vol. xxiii, p, 232. 



Specific Characters. — Shell turreted, solid; whorls but slightly convex; 

 ornamented by exceedingly fine spiral lines, sometimes inconspicuous or wanting, 

 and, on all but the last, by rather irregular, flattened cost^e, with a slight constric- 

 tion below the suture ; suture distinct, but not deep ; spire regularly diminishing 

 upwards ; mouth oval, angulate above, expanded l^elow ; outer lip thin. 



Dimensions. — L. 16 mm. B. 8 mm. 



Distribution. — Recent: Spitzbergen, Iceland, Greenland, Newfoundland, 

 Canada, Eastport (Maine). 



Fossil : Turbot-bank, Co. Antrim ; Aberdeen ; Udde valla. 

 Canada — Quebec, Montreal, Riviere du Loup. 



Remarks. — This arctic and circumpolar species, originally identified, though in 

 error, with the Scalaria horealis of Beck, is now generally known under the above 

 name. It has been recorded, probably as a fossil, from the Turbot-bank and from 

 the coasts of Aberdeenshire. One of the specimens now figured is from the 

 Pleistocene of the Canadian Riviere du Loup, where Sir J. W. Dawson said it was 

 abundant; the other is from the Turbot-bank and belongs to the Belfast Museum. 

 The latter is without sculpture and is slightly smaller than the Canadian fossil. 



Genus PYRAMIDELLA, Lamarck, 1799. 

 Pyramidella laeviuscula, S. V. Wood. Plate XLIX, fig. 8. 



1842—74. Pijramidella lasviuscula, S. V. Wood, Ann. Mag. Nat. Hist. [1], vol. ix, p. 537, 1842 ; 

 Mon. Crag Moll., pt. i, p. 77, pi. ix, tig. 2, 1848 ; 1st Suppl., pt. i, p. 57, 1872 ; pt. ii, p. 182, 1874. 



1871. Pyramidella imiplicata, Jeffreys in Prestwicli, Quart. Journ. Geol. Soc, vol. xxvii, pp. 145, 490. 



1872. Pyramidella iMcosa, A. and R. Bell, Proc. G-eol. Assoc, vol. ii, pp. 204, 210. 

 1874. Pyramidella 2^1 icosa. Van den Broeck, Ann. Soc. malac. Belg., vol. ix, pp. 120, 135. 



