1892.] NATURAL SCIENCES OF PHILADELrHIA. 391 



aaa. $ system lacking accessories ; $ system having epi- 

 phalluson penis ; no appendix. 



Group IV, Epiphallophora. 

 aaaa. $ and ^ genital systems lacking all accessory organs. 

 b. Jaw soldered into one piece. 



Group V, Haplogona.* 

 bh. Jaw composed of 16-24 separate plates. 



Group VI, POLYPLACOGNATHA. 



Group I, MACROON" Pilsbrj. 



Manual of Conchology (2), YI, p. 57, 1890. 



Arboreal or ground living Helicoids, reproducing by eggs of 

 relatively very large size (one-fourth to over one-third the diameter 

 of the adult shell) and few in number ; sometimes viviparous. 

 The embryonic shell is correspondingly large, and sculptured differ- 

 ently from the subsequent growth. Some genera now classed with 

 the Bulimi may prove to belong here, besides the following : 



Genus ACAVUS Montfort. 



Oviparous ; genital organs lacking all accessory appendages ; 

 duct of the spermatheca short. Jaw smooth. Teeth all simply 

 unicuspid. 



Subgenus PYROCHILUS Pilsbry.7 



This group will probably prove to be a section or subgenus of 

 the Ceylonese genus, as Dr. v. Moellendorff has pointed out. It is 

 still unknown anatomically. 



Genus STYLODONTA C. & J. 



Viviparous; 9 genital system lacking accessory appendages, but 

 $ system having a flagellum upon the penis ; duct of the sperma- 

 theca long. Jaw not ribbed. Median teeth unicuspid, but margi- 

 nals bluntly trifid. 



Distribution : Seychelles Islands. 



Genus HELICOPHANTA Fer. 



Group II, BELOGONA. 



Female genitalia provided with one or two dart-sacks and mucous 

 glands. 



'This name is proposed to supersede Phania Albers, 1860, that term being pre- 

 occupied for an apparenlly valid genus of Diptera described by Meigen in 1824. 

 Type , Helix pyrostoma . 



