300 Mr. K. Etheridge, Jim., on Gasteropoda. 



the striae dying out, immediately they pass on to the body of 

 the shell, into mere fine stria? of growth. The inner lip is 

 reflected and thickened, transversely obliquely ridged, and 

 with a small callosity near the upper angle. Spire elongated. 

 Prof, de Koninck appears to have been one of the few authors 

 who have noticed the transverse oblique ridges on the inner 

 lip of this species. It is the 



Natica plicistria, Phillips, as above. 



Natica plicistria, var. 0, Portlock, Geol. Report, 1843, p. 420, t. 31. 



Naticopsis plicistria, M'Cov, Synop. Carb. Limest. Foss. Ireland, 1844, 



p. 34. 

 Nerita plicistria (pars), De Koninck, Aniniaux Foss. p. 483, t. 42. 



fig. 3, a-c. 

 Naticopsis plicistria (pars), M'Coy, Brit. Pal. Foss. 1853, fasc. iii. 



p. 544. 

 Natica plicistria, Morris, Cat. Brit. Foss. 1854, p. 263. 



Natica variata, Phillips (p. 224, t. 14. figs. 26 & 27). 



There does not appear to be any definite type example of 

 this species preserved in the collection. It is the 



Natica variata, Phillips, as above. 



? Nerita variata, De Koninck, Animaux Foss. p. 481, t. 32. fig. 8, a, b. 



Naticopsis variata^VCoj, Brit. Pal. Foss. 1853, fasc. iii. p. 544. 



Natica elongata, Phillips (p. 225, t. 14. fig. 28). 



The figure of this species is not a good one. By several 

 authors N. elongata has been placed as a synonym of N. 

 plicistria ; but they are quite distinct : the structure of the 

 inner lip is sufficient to prove this, irrespective of other charac- 

 ters. In the present species it is very much reflected and 

 thickened, with a large, prominent, blunt tubercle or callosity 

 placed high up ; the surface of the lip is plain and without 

 any transverse ridges. In addition to this the apex of the 

 shell is mamillary, and the body-whorl more or less con- 

 cave about the middle ; the latter character varies to some 

 extent. It is the 



Natica elongata, Phillips, as above. 



Natica plicistria, var. a, Portlock, Geol. Report, 1843, p. 420, t. 31. 



fig. 6. 

 Nerita plicistria (pars), De Koninck, Animaux Foss. p. 483, t. 42. 



fig. 3, a-c. 

 Naticopsis plicistria, M'Coy, Synop. Carb. Limest. Foss. Ireland, 1844, 



p. 34 ; (pars) M'Coy, Brit. Pal. Foss. 1853, fasc. iii. p. 543. 

 Natica plicistria, Morris, Cat. Brit. Foss. 1854, p. 263. 



Natica tabulata, Phillips (p. 225, t. 14. fig. 29). 



The only specimen in the collection is smaller than the 

 figure given in the ' Geology of Yorkshire,' and has portions 



