CLATHURBLLA LINEARIS. 237 



which cross the ribs ; suture fairly deep ; mouth oval with a small angulate notch 

 above; outer lip thickened by the labial rib, smooth within; canal short and open. 



Dimensions. — L. 10 — 12 mm. B. -5 — 6 mm. 



Distribution. — Recent : Mediterranean, Adriatic. 



Fossil : Waltonian Crag : Little Oakley. 



Upper Phocene : Italy — Monte Mario ; Sicily— Altavilla. Pleistocene : Tunis. 



B«mar/cs.— This form, regarded by M.M. Dautzenberg, Dollfus, the Marchese 

 di Monterosato and others as a distinct species, was held by Jeffreys {op. cit.) to 

 be identical with G. Leufroiji. I follow the authorities named in separating it from 

 the latter. My Crag fossil has been identified by M. Dautzenberg, who has kindly 

 sent me a Recent specimen from the Mediterranean for comparison. Prof. Kobelt, 

 on the contrary, regards 0. concinna as a variety of C. linearis. The former has 

 not been recorded from British seas. 



Clathurella linearis (Montagu). Plate XXVIII, figs. 26—29. 



1803. Murez linearis, Montagu, Test. Brit., pt. i, p. 261, pi. ix, fig. 4. 

 1803. Murex elegans, Donovan, Brit. Shells, vol. v. pi. clxxix, fig. 3. 

 1848. Plexirotoma linearis, S. V. Wood, Mon. Crag Moll., pt. i, p. 56, pi. vii, fig. 2. 

 1853. Mangelia linearis, Forbes and Hanley, Brit. Moll., vol. iii, p. 470, pi. cxiv, figs. 1 — 3. 

 1867. Befrancia linearis, Jeffreys, Brit. Conch., vol. iv, p. 368, pi. Ixxxix, fig. 2. 



1878-5. Defrancia linearis, Seguenza, Boll. K. Com. Greol. Italia, vol. iv, p. 298, no. 125, 1873 ; vol. v, 

 p. 276, no. 42, 1874; vol. vi, p. 208, no. 187, 1875. 



1877. Homotoma elegans, Bellardi, Moll. Terr. Terz. Pieni., pt. ii, p. 271. 



1878. Clathurella linearis, Gr. O. Sars, Moll. Reg. Arct. Norv., p. 218, pi. xxiii, fig. 2. 



1883. Clathurella linearis, Bucquoy, Dautzenberg et Dollfus, Moll. mar. Kouss., vol. i, p. 96, pi. xiv, 



figs. 20, 21. 

 1S90. Clathurella linearis, Carus, Prod. Faun. Medit., vol. ii, p. 426. 

 1901. Clathurella linearis, Br(z(gger, Norges geol. unders0gelse, vol. xxxi, p. 661, pi. xvii, fig. 15 ; 



pi. xviii, fig. 18. 

 1905. Clathurella {Cirillia) linearis, Kobelt, Icon, schalentrag. europ. Meeresconch., vol. iii, p. 367, 



pi. xcvi, figs. 13 — 15. 

 1910. Peratotoma {Cirillia) linearis, Cerulli-Irelli, Palaeont. Ital., vol. xvi, p. 59, pi. v, figs. 39 — 45. 



Specific Characters. — Shell small, solid in the type form; whorls convex, the 

 last much the largest, three-fifths the total length, ornamented by strong, thick 

 and prominent longitudinal ribs, granulated and equal to the spaces between them, 

 ten to twelve on the body-whorl, and by thread-like and regular spiral lines ; 

 suture deep ; mouth pyriform ; canal short, open, turning to the left ; outer lip 

 thick, crenellated by the spiral ridges ; inner lip slight and retired ; pillar flexuous. 



Dimensions. — L. 8 mm. B. 4 mm. 



Distribution. — llecent : generally distributed on the southern coasts of Great 

 Britain, less frequently on the northern. North Atlantic from Iceland and Finmark 

 to Madeira and the Canaries. Mediterranean, Adriatic, ^gean. 



