NASSA RETICOSA. 01 



longitudinal costie, rather oblique, equal to the spaces between them, 20 to 25 on 

 the body whorl, which with the canal is somewhat less than half the total length, 

 and by numerous thread-like spiral lines in the interspaces, closely crowded 

 together both internally and externally ; suture Avell-marked and channelled l)ut 

 not deep ; mouth pyriform, acutely angulate above, ending abruptly in a straight 

 and exceedingly narrow canal. 



Dimensions. — L. 28 mm. B. 7 mm. 



Distribution. — Not known living. 



Fossil : Waltonian Crag : Walton-on-Naze, Beaumont, Little 

 Oakley. Newbournian : Waldringfield, Newbourn, Ramsholt, Sutton, Felixstowe. 



Bemnrls. — This form, of which Wood had obtained a few examples only from 

 the Newbournian Crag of Sutton and Felixstowe, was figured by him from an 

 immature specimen. Since then many more have been found at Walton, Beaumont 

 and Oakley ; I have fifty from the last-named place, most of them worn or 

 imperfect ; some, however, are in a sufficient state of preservation to show the long, 

 narrow canal and the delicate spiral sculpture of the shell. 



B. gracilenta is not known from the Coralline, and our fossils have an appear- 

 ance of being derivative in the Red Crag, as, indeed. Wood believed them to. be. 

 The difficult}" in accepting this view is the comparative abundance in which they 

 occur at Oakley. It is not easy to understand that there could have been an older 

 fossiliferous deposit at no great distance from the Red Crag shore yielding so 

 many specimens of this form, which did not afford also an equal or similar number 

 of other characteristic species. 



The specimen here figured, which is better preserved than that given by AYood, 

 is from AValdrino-field. 



Genus NASSA, Lamarck, 1799. 

 Nassa reticosa (J. Sowerby). 



1818. Buccitiuin reticosum, Buccinum eloncjatum, Buccinum rugosum, J. Sowerby, Min. Couch., vol. ii, 



pp. 15^17, tab. ex, figs. 1—3. 



1848. Nassa reticosa, S. V. Wood, Men. Crag Moll., pt. 1, p. 33, tab. iii, figs. 10 o— 10 /;. 



1881. Nassa reticosa, Nyst, Conch. Terr. Tert. Belg.,p. 12, pi. ii, fig. 4. 



1885. Nassa reticosa, Loric, Arch. Mus. Teyler [2], vol. ii, p. 199, pi. v, figs. 19—22. 



1890. Nassa reticosa, A. Bell, Eep. Brit. Assoc. (Leeds), p. 410. 



1892. Nassa reticosa, Van den Broeck, Bull. Soc. Belg. Geol., vol. vi (Meuioires), pp. 120, 131. 



1894. Nassa serrata, Kendall, Journ. Isle of Man Nat. Hist. Soc, vol. i, p. 419, pi. i, figs. 1 — 3. 



1912. Nassa reticosa, Tesch, Med. v. d. Rijks. v. Delfstoffen, pt. iv, p. 78. 



Specific Characters. — See Mon. Crag Moll., pt. i, p. 33. 

 Dimensions. — L. 30 — 60 mm. B. 15 — 30 mm. 

 Distribution. — Not known living. 



