HISTORICAL SKETCH. XXI 



Heliceen, edited by von Martens, marked a period closed, and a new 

 <epoch begun. 



As the classification given in this work has been the basis of nearly 

 all subsequent systematic arrangements, it is here quoted in full 

 The brackets indicate that groups so united are supposed to be- 

 closely allied. For purposes of comparison I have given in Roman 

 type the names of the super-generic groups of this volume, under 

 which each of the Albers Martensian subgenera falls, these groups 

 being as follows : 



Endodontidce : Haplogona, Polyplacognatha. 

 Helicidce: Protogona, Teleophallogona, Epiphallogona, Belogona 



(with two divisions, Bel. Euadenia and Bel. Siphonade- 



nia), Macroogona. 



Vitrinea. 



Oenus SAGDA Beck (Teleophallogona). 



Hyalosagda, Proserpinula, Odontosagda. 

 Genus LEUCOCHROA Beck (Belogona). 



Helicacea, 



' Acanthinula, Belogona. 

 Vallonia, Belogona. 

 Petasia, Belogona. 

 Frutiricola, Belogona. 

 Dorcasia,Protogon a & Belogona. 

 Epiphallogona. 



Genus HELIX L. 



( Amphidoxa, Haplogona. 

 j Mierophysa, Teleophallogona. 

 j Aerope, Rhytididse. 

 ^ Pella, Haplog. & Zonitidse, etc. 

 f Patula, Haplogona. 

 j Charopa, Haplogona. 



j Stephanoda, Haplogona. C Xerophila, Belog. Siphonadenia. 



[Rhytida, Rhytididse. -j Turricula, Belog. Siph. 



Jatiulus, Zonitidse. (_ Cochlicella, Belog. Siph. 



Endodouta, Haplogona. ( Ochthephila, Belogona. 



Sesara, Zonitidse. < Actinella, Belogona. 



Pelia, Zonitidse. (_ Tectula, Belogona. 



Gonostoma, Belog. si phonadenia. | Plectotropis, Belog. Euadenia. 



Ophiogyrd, Protogona? \ Aegista, Belog. Euad. 



< Polygyra, Protogona. ( Aglaia, Belog. Euad. 



\Stenotrema, Protogona. j Campy Icea, Belog. Siph. 



{Triodopsis, Prolog. & Belog. j Eurycampta Belog. Euad. 



Mesodon, Protogona. \^Arwnta^ Belog. Siph. & Euad. 



Laoma, Polyplacognatha. Eurystoma, Epiphallogona. 



