70 PLIOCENE MOLLUSCA. 



prominent longitudinal ribs, crossed by numerous exceedingly fine spiral striations, 

 closely crowded together ; apex acute ; suture deep and undulate ; moutli ovate ; 

 outer lip thickened externally by a broad labial rib, grooved within ; canal very 

 short, turning to the left. 



Dimensions. — L. 15 mm. B. 10 mm. (occasionally larger). 



Distribution. — Recent : Mediterranean, Adriatic, ^gean ; coasts of western 

 Europe; Madeira; Canaries. 



Fossil : Coralline Crag; Gedgrave, Boyton. Waltonian : Walton- 

 on-Naze, Little Oakley. Newbournian : Sutton, Newbourn (Ogden), 



Pliocene : Italy ; Sicily, Rhone valley. Pleistocene : Sicily. 



Remarlcs. — The Crag JV. Hmata seems to be specially characterised by its 

 exceedingly fine and closely crowded spiral sculpture, in which respect our fossils 

 correspond with the living shell. One of the former is here represented, together 

 with a specimen from the Mediterranean kindly sent me by Dr. Eisig of the 

 Stazione Zoologica at Naples ; a comparison of these figures Avith those of N. 

 prisinatica will show the difference between the two. 



Var. anomala, no v. Plate IV, fig. 3. 



Dimensions. — L. 15 mm. B. 8 mm. 



Distribnfion. — Not known living. 



Fossil: Coralline Crag. Waltonian: Little Oakley. Newbournian: 

 Newbourn. 



liemnrlis. — In this abnormal variety of N. liinafa, of which I have obtained about 

 a dozen specimens at Oakley, some of the delicate and inconspicuous spiral lines 

 anastomose for a short distance, forming a series, about a third as numerous, of 

 wide, strongly marked transverse ribs, separated by furrows of equal width wliicli 

 nearly obliterate the longitudinal costfe ; a varix is then formed, after which the 

 normal growth recommences, but the process is repeated just before the formation 

 of the mature moutli ; otherwise the shell agrees with the type. I have received an 

 imperfect but recognisable specimen of this variety from the Messrs. Ogden, which 

 they found at Newbourn. 



Nassa ssrrata (Brocchi). Plate III, figs. 5, 6. 



1814. Buccinum serratum, Brocchi, Couch, foss. subap., p. 838, pi. v, fig. 4. 



1836-44. Buccinum serratum, Philippi, Eii. Moll. Sic, vol. i, p. 225; 1836; \o\. ii, p. 191. 1844. 



1848. Nassa monensis (!), S. V. Wood, Mou. Crag Moll., pt. i, p. 31, tab. iii. fig. 5. 



1870. Nassa serrata, A. Bell, Joiirn. de Conch., vol. xviii, p. 34-5. 



1873-75. Nassa serrata, Seguenza, Boll. R. Com. Geol., vol. iv, p. 300, 1873; vol. vi. p. 278, 1875. 



1882. Nassa serrata, Bellardi, Moll. Terr. Terz. Piem., pt. iii, p. 67, pi. iv, fig. 17. 



1912. Nassa serrata, Tesch, Med. v. d. Rijlcs. v. Delfstoifeu, pt. iv, p. 78. 



