74 PLIOCENE MOLLUSCA. 



the others as in N. j^roplnqna. Wood remarks that in the latter the outer lip is 

 thickened and denticulated within, and that there is a small tooth on the body- 

 whorl within the mouth. Neither of these features appears in N. trivittata, but in 

 A'ery many of my specimens of N. j^rojAnqiia from Oakley the tooth is obsolete or 

 nearly so, while in none of tliem is there any marked thickening or denticulation 

 of the lip. If these forms are not varieties of one species they clearly belong to 

 the same group. 



Nassa monensis, Forbes. Plate IV, figs, 7, 8. 



1839. Nassa monensis, Forbes, Mem. Wern. Soc, vol. viii, p. 95. 



1846. Nassa monensis, Strickland, Proc. Geol. Soc, vol. iv, p. 8. 



1846. Nassa monensis, Forbes, Mem. G-eol. Surv., vol. i, p. 427. 



1894. Nassa monensis, Kendall, Journ. Isle of Man Nat. Hist. Soc, vol. i, p. 419, pi. i, tigs. 10 — 13. 



1903. Nassa monensis, Lamplugb, Mem. G-eol. Survey, Isle of Man, p. 475, fig. 82 (p. 336). 



Specific Characters. — Shell ovate, small, solid and strong: whorls five or six, 

 slightly concave, ornamented by a few narrow but prominent and distant ribs, 

 varying in number, and by fine spiral thread-like lines which produce granulation 

 where they intersect; mouth ovate, notched above ; outer lip thickened outside 

 by a strong labial rib, denticulated within ; canal very short and ol)lique. 



Dimensions. — L. 16 mm. B. 10 mm. 



Distribution,. — Not known living. 



Fossil : Waltonian Crag : Little Oakley. Newbournian : New- 

 bourn. ^ Cranstal Point and elsewhere, Isle of Man. 



BemarJcs. — There seems to have been an error as to the fossil figured by "Wood 

 in his Monograph (pt. i, p. 31, tab. iii, fig. 5) as 1^. monensis. He states in his 

 first Supplement (p. 15) that being unable to trace the specimen upon which this 

 species was originally founded, his identification must be regarded as uncertain. 



In 1894, however. Prof. Kendall described some Nassa s he had found in the 

 Manx drift which he considered the true N. monensis of Forbes. As they differ 

 widely from Wood's shell, and considerable confusion has arisen on the subject 

 both in this country and on the continent, it seems desirable to figure a specimen 

 Avhich Prof. Kendall has kindly sent me, with another, not quite perfect, from Oakley, 

 which corresponds with it. It is a special form and different from anything I know 

 from the Crag. Mr. Lamplugh's figure does not correctly represent the present shell. 



The N. monensis of Morch (Geol. Mag., 1871, p. 397) is quite different; I have 

 referred it in the sequel to N. lameUilabra, Nyst. 



Nassa Kermodei, Kendall. Plate XIII, fig. 17. 



1894. Nassa Kermodei, Kendall, Journ. Isle of Man Nat, Hist. Soc, vol. i, p. 419, pi. i, figs. 14 — 17. 

 1903. Nassa Kermodei, Lamplugh, Mem. Geol. Surv., Isle of Man, p. 475, fig. 83, p. 336. 



^ Mr. Ogden has recetitly seut to me a specimen of the present species from Newbourn. 



