APPENDIX. 



ARTIFICIAI. TABLE. 



This Artificial Table is merely intended to assist the student in 

 the discovery of the genera, without any reference to their 

 natural relations. The numbers refer to the pages in the body 

 of the work. 



I. UNIVALVES. 



Shells consisting of a more or less conical valve. 



A. Shell flat, solid. 

 LiMAX. Shell oval or oblong, without any visible spire. — p. 75. 



B. Shell conical. 

 Ancylus. Shell conical, apex recurved rather to the right. — 

 p. 216. 



Velletia. Shell conical, compressed , apex subcentral, bent 

 to the left. — p. 220. 



C. Shell ear-shaped^ solid. 

 Testacella. — p. 53. 



D. Shell conical., spiral. 

 a. Shell thin, edge of lips not thickened or reflexed, pei'istome 

 not continued. 



* Month transverse, lunate ; shell depressed. 



ViTRiNA. Shell imperforated ; mouth large. — p. 85. 



Zonites. Shell perforated, or umbilicated ; mouth moderate. 

 — p. 89. 



(Helices, Pupa, Clausilia, &c., when yomig.) 



