102 Mr. H. Woodward on the Tertiary Shells 



CONCHIFERA. 



Fam. Corbulidae. 



1. Pachydon, Gabb. 1\ erectw, Conrad. 



P. te)niis, Gabb. P. ciineatus, Conrad. 



P. carinaius, Conrad. P. ovatus, Conrad. 

 P. obliquus, Gabb. 



1. IscBGy Conrad, Amer. Journ. Conch. 1870, pi. 10. 

 figs. 6, 10, 13. 



In the series before us we have no representatives of this 

 genus. The figures given in Mr. Conrad's plate are not worth 

 reproducing, having evidently been drawn hurriedly and with- 

 out sufficient care. 



Mr. Conrad presumes this form to be a freshwater shell 

 closely allied to Tricida, Benson, found in India. 



2. Liris^ Conrad, op. cit. pi. 10. fig. 3. 



The figure indicates a shell about 2 lines in length. These 

 two shells, Mr. Conrad considers, probably belong to the 

 Melaniidae. 



3. Ehora crassilabra, Conrad, oj>. cit. pi. 10. fis:. 14. 

 PI. V. figs. la,b. 



"Shell turbinate; columella much arched; peristome con- 

 tinuous, thickened ; aperture notched at base." We venture 

 to refer the specimen figm-ed on our plate (figs. 1 a, b) to this 

 species ; but Mr. Conrad's figure is very obscure. We have 

 three specimens, all of which are umbilicated and the mouth 

 veiy much produced. 



This little shell closely resembles Lacuna, a Xorth-American 

 genus inhabiting brackish water. 



The one selected for our figure indicates the presence of 

 another Gasteropod of the family Buccinid^e, or Natica, as 

 evidenced by the perforation in its whorl. This is most impor- 

 tant, as Mr. Conrad expresses his inability to decide whether 

 Ebora be a marine or freshwater genus. 



Length 4 lines, breadth 3 lines. 



3 a. (Subgenus) Nesis bella, Conrad, op. cit. pi. 10. fig. 17. 

 PI. Y. fig. 3. 



" Last whorl ornamented with seven prominent revolving 

 ribs, the intermediate spaces concave ; spire consisting of four 

 volutions, flat towards the apex, two ribs on each except the 

 apical whorl and the next, which are smooth." 



We do not po.ssess a specimen of this shell ; but its form, 

 which is very characteristic, leaves little doubt that it is refer- 



