ADMF/FE VIRIDULA. 40? 



Specific Characters. — Shell fairly solid, ovato-fusiform ; whorls about 7, convex, 

 the last more or less ventricose, excavated below ; varying considerably in 

 sculpture, generally ornamented by prominent oblique and obtuse longitudinal 

 costae which die out on the body-whorl, and always by irregular spiral ridges 

 which extend to the base ; spire elongato-conical, ending in a fine rounded apex ; 

 suture deep ; month oval, passing into a short and najrrow canal ; outer lip thin ; 

 folds on the columella obscurely triplicate. 



Dimensions. — L. 12 — 18 mm. B. 6 — 10 mm. 



Distribution. — Recent: (with varieties) Hebrides (Jeffreys), Scilly (Marshall), 

 Brittany (Locard). Norwegian Coast — Trondhjem to Finmark, Lapland, Lofoten 

 Islands. Iceland, Barent's Sea, Spitsbergen, Greenland, Labrador, Hudson's Bay, 

 Davis Strait, New England coast, Behring Strait. 



Fossil: Coralline Crag: Sutton, Gedgrave, Sudbourn. Wal- 

 tonian : W;dton-on-Naze, Little Oakley. Newbournian : Waldringfield, Sutton, 

 Newbourn, Felixstow. Bntleyan : Bawdsey, Hollesley, Butley. Icenian : Norwich 

 zone — Bramevton, Postwick, Aldeby, Dunwich, Horsford. Weybourne zone — E. 

 Runton. Iceland Crag. Wexford, Isle of Man. 



Scaldisien, Poederlien : Antwerp. Dutch borings. 



Pleistocene : Bridlington, Dimlington, west Cheshire, Cleongart. Christiania 

 fiord, from Yoldia-cl&ys to Tapes-hanks. Montreal. 



Remarks. — This species, which with its varieties seems to be almost entirely 

 confined at present to northern and arctic seas, made its first recorded appearance 

 in the Anglo-Belgian region in Coralline Crag times ; it is not very rare in the 

 Waltonian of Oakley, and is generally diffused at the later horizons of the Red and 

 the Icenian deposits. It is given by Prof. Kendall from the Manx beds and by 

 Mr. A. Bell from Wexford, occurring also at Bridlington and other Pleistocene 

 localities. I have found several varieties at Oakley, one corresponding with Prof. 

 G. 0. Sars' type form {<>)>. n't., pi. xiii, fig. 1 a), and another with his variety 

 producta (fig. 2). The Crag specimens in my collection, which I group with the 

 type variety, have an elongate spire — indeed, Wood's description (spiral acuminata) 

 makes this feature specially characteristic. There is another group, described 

 below, with a short spire and a more or less ventricose body- whorl which may be 

 known, I think, as varietal under Jay's name of Couthoui/i. The Conchological 

 Society of Great Britain, however, in their list of British Marine Mollusca, have 

 united the latter with A. viridula as one species, A. Oouthouyi. 



Var. Couthouyi (Jay). Plate XXXIX, figs. 48, 40. 



1838. Gancellaria buccinoides, Couthouy,' Boston Journ. Nat. Hist., vol. ii, p. 105, pi. iii, fig. 3. 



1839. Gancellaria Couthouyi, Jay, Cat. of Shells, p. 77. 



1 The specific name buccinoides had been used previously, in 1832, by Sowerby, for a different and 

 North American shell. 



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