108 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [NoV. 7, 



B. Outer lip deeply depressed in the middle and thickened 

 internally. 



N. annulata, nobis, t. 13. f. 1. . 



N. grandis, Voltz et Bronn, Jahrb. 1836, t. 6. f. 1 ; not of Goldfuss. 



C. Outer lip furnished with an internal fold. 

 N. turbinata, nobis, t. 12. f. 2. 



Subgenus 4. Ptygmatis. 



Columella usually with three folds ; outer lip with one to three 

 folds ; one or more of the folds of a complex form, either dividing 

 into two lobes, or wider towards the edge than at the base. 



A. Columella solid. 



N. bifurcata, D'Orb. T. Cret. t. 160. f. 4, 5. 



N. Conimbrica, nobis, t. 13. f. 4. 



N. Eschwegii, nobis, t. 13. f. 2. 



N. Fleuriausa, D'Orb. T. Cret. t. 160. f. 6, 7. 



N. Olisiponensis, nobis, t. 13. f. 3. 



N. triplicata, Voltz et Bronn, Jahrb. 1836, t. 6. f. 24. 



B. Columella umbilicated. 



N. Bruntrutaria, Thurm. 17 ; Bronn, Lethsea, t. 21. f. 13 ; Voltz et 



Bronn, Jahrb. 1836, t. 6. f. 13, 18 ; Goldf. t. 1 75. f. 5. N. hiero- 



ghjphica, Lyell, Elem. Geol. 2. p. 48. f. 246. 

 N. Bruntrutana^ D'Archiac, Mem. Soc. Geol. de France, vol. 5. t. 30. 



f. 11. 

 iV. crenata, Goldf. t. 177. f. 2.^ 

 iV. imbricata, Desh. Exp. Moree, t. 26. f. 4, 5. 

 N. Mandelslohi, Bronn, Jahrb. 1836, t. 6. f. 26 ; Goldf. t. 175. f. 4. 

 N. trachcea, Deslongch. Mem. Soc. Linn. Norm. 7. t. 11. f. 2, 3. 



N. Foltzii, D'Archiac, Mem. Soc. Geol. de France, vol. 5. t. 30. 



f. 5 ; not of Deslongchamps. 



The following species, which have been placed in Nerincea, appear 

 to belong more properly to other genera : — 



N. brevis, D'Hombres-Firmas ; D'Orb. Terr. Cret. t. 162. f. 3, 4 ; 

 has no internal fold, nor the mode of growth of the Nei'incece : as only 

 a cast has been figured it is difficult to decide on its true genus, which 

 may be Trochus or Pleurotomaria. 



N. Marrotiana, D'Orb. T. Cret. t. 163 bis, f. 1, 2, has the folds 

 on the columella only formed at certain intervals, as in Pyramidella. 



N. monilifera, D'Orb. T. Cret. t. 163. f. 4, has only a fold on the 

 top of the whorl, with the columella and the outer hp simple, as in 

 Telescopium. 



N. perigordina, D'Orb. T. Cret. t. 163 bis, f. 1, 2, belongs to Ce- 

 rithium, having the outer lip simple, and a fold on the columella, 

 which, according to the figure, is not continued through the whorls. 



