278 HYGROMIA. 



glands are inserted very high, four on each side ; some distance 

 below them are two dart sacks, with two accessory sacks, the latter 

 containing no darts. Penis, etc., as usual in the genus. The geni- 

 tal system of H. unidentata is the same as in leucozona. 



A group of Middle Europe, in which the shell has much similar- 

 ity to Dibothrion, but the genitalia are as in Frutidcola hispida, etc. 



H. unidentata Drap., iii, 171. H. leucozona Zgl., iii, 171. 



cobresiana Alt., iii, 171. coadvnata Z. 



monodon Fer. /. delopida Jan. 



villce Mu'hlf. /. crassilabris Miihlf. 



ventricosa Jan. /. rutilans Z. 



/. anodonta Tschap. modesta Parr. 



/. alpestris Cl. v. ovirensis Rin., iii, 172. 



/. subleucozona Fag. v. heteromorpha W., iii, 172, 



H. edentula Drap., iii, 171. v. erjaveci Cless., iii, 172. 



depilata Drap. H. bielzi Schm. 



liminifera Held. v. bosnensis Mlldff. 



Section Dibothrion Pfr., 1855. 



Petasia BECK, Index, 1837, p. 21. MARTENS, Die Hel., I860, p. 

 102, type H. bidens. Not Petasia Serv., 1821 (Orthoptera) of 

 Steph., 1829, (Lepidoptera) or of Morr. 1829, (Polyzoa). Trocliiscus 

 HELD, Isis, 1837, p. 915. Not Troehiscus Heyden 1826, (Arach- 

 nida). Dibothrion PFR., Mai. Bl. 1855, p. 128 (for bidens and 

 bicallosa}. 



Shell subtrochoidal, with convex-subconic spire of numerous nar- 

 row whorls, and closed or nearly closed umbilicus ; arcuate-striate, 

 translucent brown with light peripheral band. Aperture basal,, 

 narrow ; lip well expanded, reflexed, with two strong internal teeth 

 or nodules on the basal margin, marked by pits behind the lip ; 

 parietal wall toothless. Type If. bidens, pi. 55, figs. 25, 26. 



Genitalia (pi. 70, fig. 41, H. bidens) : Dart sack single, cylindrical 

 and rather large ; two mucus glands on each side. Other organs as 

 in Hygromia generally, except that the spermatheca duct is unusu- 

 ally short. Dart needle-like, with four short blades at the point. 



Distribution, eastern Europe and Siberia. 



