NATICA (POLINICES) LACTEA. 699 



a different species. It is much larger than Sowerby's type and appears to group 

 itself with X. proximo,, especially with the variety I Voodii. Philippi identities, 

 though doubtfully, A. hemielausa with a recent Mediterranean form, N. macilenta, 

 a view adopted by Seguenza but not by Wood. 



Var. oakleyensis, nov. Plate LVI, fig. 17. 



Remarks. — I have a few specimens from Oakley agreeing with the type form 

 but larger and longer, about 18 mm. by 15 mm., which I think deserve notice. 

 They might otherwise be taken for the Miocene species N. varians, described on 

 p. 696. 



Natica (Polinices) lactea, Guilding. Plate LIV, fig. 19. 



1837. Natica lactea, Guilding, Trans. Linn. Soc, vol. xvii, p. 31. 



1852. Natica lactea, Philippi, Martini und Chemnitz, Conch. Cab., ed. 2, vol. ii, p. 61, pi. x, fig. 2. 



1885. Natica (Mamma) lactea, Tryon, Man. Conch. [1], vol. viii, p. 49, pi. xv, fig. 45 ; pi. xvi, 



figs. 52, 54—57, 59 ; pi. xvii, fig. 62 ; pi. xix, fig. 85. 

 1855. Natica porcella nea, Reeve, Conch. Icon., vol. ix, pi. xxiii, no. 102. 

 1901. Natica (Mamma) lactea, Kobelt, Icon, schalentrag. europ. Meeresconch., vol. ii, p. 107, pi. lvii, 



figs. 7—11. 



Specific Characters. — Shell ovate, strong, smooth ; whorls 6, the upper ones 

 but slightly convex, the last ventricose, much the largest ; spire very short with a 

 small, pointed apex ; suture slight; mouth oblong, semilunar, nearly half the total 

 length of the shell, angulate above, rounded below ; outer lip gently curved ; 

 umbilicus longer than wide, open, deep, partly closed by a thick callus. 



Dimensions. — L. 20 mm. B. 16 mm. 



Distribution. — Recent : warmer part of the N. Atlantic, Madeira, Antilles, 

 Canaries, Isthmus of Corinth. 



Fossil : Taranto, Calabria (Seguenza), St. Erth. Algiers (?). 



Remarks. — The specimen here figured belongs to the British Museum and was 

 found at St. Erth, and has been identified by M. Dautzenberg with this southern 

 species. It agrees very nearly with a specimen of a West Indian shell from his 

 collection which he informs me came from the Antilles. It is not the only case 

 of the kind in the Crag fauna, as, e. g., Erato maugeriss, another West Indian form. 



Genus ACRYBIA, H. and A. Adams, 1853. 

 Acrybia Smithii (Brown). Plate LV, fig. 9. 



1838. Bulbus Smithii, Smith, Mem. Wern. Nat. Hist. Soc, vol. viii, p. 56, pi. i, fig. 18. 

 1839—49. Globitl/i* Smithii, Brown, Mem. Wern. Nat, Hist, Soc, vol. viii, p. 104, pi. i, fig. 18, 1839 

 111. Foss. Conch., p. 256, pi. xxxiii, fig. 77, 1849. 



