XX11 



HISTORICAL SKETCH. 



Euparypha, Belog. Siph. 

 C lachea, Belog. Siph. 

 x Macularia Belog. Siph. 

 ( Iberus, Belog. Siph. 



Coryda, Belog. Euadenia. 

 ( Hemicycla, Belog. Siph. 

 j Plebecula, Belog., Si ph.? 

 (_ Leptaxis, Belog. Siph. 



Pomatia, Belog. Siph. 

 ( Thelidomus, Epiphallogona. 



Cystieopsis, Belog. & Teleoph. 



Plagioptycha, Belog. Euad. 



Polymita, Belog. Euad. 



Liockila, Epiphallog. & Belog. 

 ^Eurycratera, Epiphallogona. 



Polydontes, Epiphallog. 

 f Helicophanta, Macroogona. 



Panda, Macroogona. 



Stylodon, Macroogona, Belog. 



Erepta, Zonitidse. 



Dentellaria, Epiphallogona. 



Cepolis, Belog. Euad. 

 ^Pleurodontn, Epiphallogona. 



Anostoma, Pupidse. 



f Labyrinthus, Epiphallog. 

 j Isomeria, Epiphallogona. 

 | Caracal us, Epiphallogona. 

 (_ Phania, Macroogona ? 

 f Thersites, Epiphallogona. 

 I Merope, Epiphallogona. 

 f Obba, Epiphallogona. 

 -< Trachia, Epiphallogona. 

 (^Planispira, Epiphallogona. 



P/iasis, Haplogona ? 



Cfiloritis, Epiphallogona. 



Pedinogyra Macroogona. 



Ampelita, Macroogona. 



Solar apsis, ? 



( Camena Epiphallog., & Belog. 

 < Hadra, Epiphallog., & Belog. 

 (_Papuina, Epiphallog. 

 f Leptoloma, Belog. Euadenia. 

 j Geotrochus Epiphallog. & Belog. 

 (_ Cymotropis, Epiphallogona. 

 f Chlorata, Belog. Euadenia. 





Cbrcuto, Belog. Euadenia. 

 Axinn, Belog. Euadenia. 

 Cullicochlias, Belog. Euadenia. 



Genus COCHLOSTYLA Fer. Belogona Euadenia. 



The general plan of this arrangement is to establish a series lead- 

 ing from Zonitoid to Bull moid shells; and the characters mainly 

 depended upon in the formation of groups are texture, form of lip, 

 and general contour of shell. In the appreciation of that indefin- 

 able something, which counts for so much in classifying Helices, the 

 authors of Die Heliceen are far beyond all previous work ; and it is- 

 this quality this accurate feeling for subtle affinities for which no 

 good reason can be given in words that has rendered this work the 

 basis of classification for three and a half decades, a long period in 

 so changeable a science as malacology. 



It would be obviously unfair to criticise this great work by stand- 

 ards of the new anatomical classification, for excepting the Haplo- 

 gona, Protogona and Belogona, the Helices were practically unknown 

 anatomically in 1860. Compared with the new system, it is note- 

 worthy that the Haplogona are mostly grouped together near the 

 Zonitidse, where they unquestionably belong; and many other felic- 

 ities of grouping will be obvious to one looking over the list, besides- 

 the genius shown in forming natural subgenera, already referred to. 

 For the rest, the Epiphallogona, Belogona, Teleophallogona, Proto~ 



