Acta Societatis pro Fauna et Flora Fennica, XIII. n:o 7. 149 



et infra medium anoustata, acuminata et producta, postice 

 latissima, margine arcuato-descendens, ad basin rotundato- 

 angulata, marg. superiore curvato; umbones lati, breves, sur- 

 sum lente attenuati, mitrellis magnis, inflatis. Long. 1^1^, 

 alt. 6, cr. 4 mm. 



Hah. Suecia in Oland (ad Bjornhofda). — Dania in Sjacl- 

 land (P'uurso, Skjelskor &c.) et Jylland (ad Viborg). 



Forma tnajo)\ long. 10 mm. — Dania in Sjeelland (ad Bronds- 



holmsdal et Boserup). 

 Var. stnctum Norm. ap. CI. 'Cliemn. Conch. Cab., 1877): c. or- 



bitn typi, ventricosissima, angulis rotundatis, nmbonibus 



brevissimis, latissimis, mitrellis magnis; long. 5. alt. 4^0, 



cr. 37-2 mm. — Dania in ins. Bornholm. 



Gen. Pisiclium C. Pfr. 



C. plus minusve incequilatera (antice semper longior), 

 ligamento parti hreviori insito. Animal siphone simplicl, 

 hrevi^ cylindraceo. 



1. Fluminina CI. C. solida, costata. dentibus cardinalihus val- 

 vulce utriusque duobus juxfa positis. 



P. amnicum Miill. (Verm. Hist. II, 1774, Tellina). C. valde in- 

 8equilatera, perobliqua, ovalis, sat ventrosa, nitida, fusco- 

 cinerea, zonis nigrescentibus, striato-sulcata, antice elon- 

 gata, deorsum forte declivis et angustata, superne late ro- 

 tundata, postice brevissima, subverticaliter truncata, con- 

 vexiuscula, margo ventralis arcuatulus; umbones lati, pa- 

 rurn prominentes. Long. 11, lat. 8, cr. 6 mm. 



Hah. Suecia, forma typica in Dalarne (in par. Gustaf et 

 in Ljusteran ad Sater), in Upland (Upsala ad Flottsund) et ad 

 Pitea. Nondum aliis locis peninsulse reperta. — Bania in Sjael- 

 land (locus orginalis Miilleri est amnis ad Fredriksdal). — Fen- 

 nia in lacubus Ylane, Saimen, Ladoga et Onega (Mus. Helsingf.). 



Var. glaciale W. (Nachr. blatt Mai. Ges., 1893): c. brevior, la- 

 tior, rotandior, margine ventrali forte arcuato, parte an- 

 teriore late rotundato; long. 9, alt. 7. cr. 3% mm. — Fen- 

 nia borealis circa 69° lat. bor. (ad Ivalojokki * Kamasjokki, 

 Enare &c.: Ch. R.). 



