SVELTIA LAJ'ONKAIREI. -^7 



sculpture is rather variable, some specimens being merely spirally striated, in some 

 the longitudinal costse extend nearly to the base of the shell, while in others thej 

 are confined to the upper whorls. Prof. Sacco figures ( .» varieties, differing in 

 sculpture, but all maintaining the same general character. 



Yar. costata, nov. Plate XXXIX, fig. 41. 



Varietal Characters. — Differs from the type form in the longitudinal costation 

 of the whorls. 



Distribution. — Fossil: Coralline Crag: Gedgrave, Boyton (A. Bell). Wal- 

 tonian : Little Oakley. Newbournian : Felixstow. 



Genus SVELTIA, Jousseaume, 1888. 



Sveltia Lajonkairei (Nyst). Plate XL, figs. 18—21. 



1835-81. CanceUaria Jonlcairiana, Nyst, Rech. Coq. foss. d'Auvers, p. 29, pi. v, fig. 28. 1835 ; C.vari- 

 cosa, Coq. foss. Belg., p. 475, pi. xxxviii, fig. 20, 1843; C. Lajonkairii, Conch. Terr. tert. Belg., 

 p. 9, pi. i, fig. 6, 1881. 



1848-50. CanceUaria coroncda, S. V. Wood, Mon. Crag Moll., pt. i, p. 64, pi. vii, fig. 18, 1848 ; 

 C. scalaroides, pt. ii, p. 316, pi. xxxi, fig. 9, 1850. 



1856. CanceUaria scalaroides, Beyrich, Zeitschr. Deutsch. Greol. Gesell., vol. viii, p. 577, pi. xviii, fig. 5. 



1880. CanceUaria varicosa, Foiitannes, Moll, plioc. Vail, du Rhone, vol. i, p. 158, pi. ix, fig. 6. 



1892. CanceUaria Lajonkairei, Van den Broeck, Bull. Soc. Beige Ceol., vol. vi (Memoires), p. 120. 



1896. CanceUaria Lajonkairi, Bernays, Bull. Soc. Beige Gcol., vol. x (Memoires), pp. 128, 131. 



1912. CanceUaria Lajonkairei, Tesdi, Med. v. d. Rijks. v. Delfstoffen, no. 4, p. 86, no. 214. 



Specific Characters. — Shell strong and solid, squarely turreted, subfusiform ; 

 wdiorls 7, convex, the last nearly two-thirds the total length, regularly diminishing 

 in size upwards, obtusely angulate above, with a distinct but narrow shelf below the 

 suture; ornamented by or 10 strong lamelliform ribs, oblique or sinuous, extend- 

 ing to the suture and to the base of the shell and by fine spiral ridges which in 

 specimens from the Red Crag are generally abraded or obsolete ; suture deep ; 

 mouth more or less squarely angulated by the keel ; outer lip grooved within ; 

 columella with two prominent folds. 



Dimensions. — L. 25 — 42 mm. B. 8—20 mm. 



Distribution. — Not known living. 



Fossil : Coralline Crag : Gedgrave, Sudbonrn, Boyton. Waltonian; 

 Walton-on-Naze, Beaumont, Little Oakley. Newbournian : Waldringfield, Sutton,. 

 Foxhall. Butleyan : Butley. 



Miocene : North Germany. 



Pliocene: Rhone Valley. Scaldisien — zone a Isocardia cor .■ Belgium. Scaldisien :. 

 Dutch borings. 



