24 C. A. WESTERLUND, SIBIRIENS LAND- OCH SÖTVATTEN-MOLLUSKER. 
Dimens.: 
Long. 52, lat. 40, apert. long. 31, lat. 27 mm. 
») BISON Hag ND » + 28, »::24 mm. 
» In AB ne ra » 24 I syy21ö mm. 
enig BID » fta207; ul ) T8omm: 
B. limmeoides SCcHR.: testa prec. similis sed imperforata, minor, margine interno 
plica elongato przedito, umbilico majori; — uncini radulx medii parte basali 9—10 
dentibus pliceformibus, parte. recurvato integri, laterales hamati, medio latiores, margi- 
nales hamati. 
Dimens:: 
Long. 32, lat. :26, apert. long. 19, lat. 17: mm. 
Pilslu Pn kt HR » eld HR L4ARN 
» SL. KN LÖN » 12, 0 mm 
B. baicalensis GERSTF.: testa imperforata, minima, ovata, margine interno callo 
longo obliquo munito; operculo majore; — uncini radulx medii parte basali 5--6 den- 
uibus pliceformibus, parte recurvato dentibus nonis secundarus, laterales plani apice 
recurvato. 
Dimens.: 
Long. 24, lat. 21, apert. long. 15, lat. 14 mm. 
AA ML RR AA Log » vr 1550, ”Lövmram, 
pr = HONA HE Oda » dör DÅ LPMIID: 
» AT LA » Aila, Pat 2 MN: 
+Hydrobia martensiana nov. sp.: testa globoso-ovata, lutescenti-albida, cornea vel 
olivacea, dense transversim striata, sepe distanter flexuoso-plicata; anfr. 3—4, celeriter 
accerescentes, cylindracei, ultimus maximus, ventricosus; spira perbrevis; apertura ovata, 
peristomate continuo, aftixo. 
Dimens.: 
Long. 12, lat. 11, apert. long. 8, lat. 6 mm. 
» 1 hl Bra LO » » (6 VV NVS, 
» STEN WIRE Di. FÖ, DE 4 NI 
+H. maxima nov. sp.: testa conoideo-globosa, pallide lutescenti-viridea vel ferru- 
ginea, sericea, tenue striata; anfr. 5, sat celeriter accrescentes, valde convexi; apertura 
oblongo-rotundata, peristomate continuo, affixo. 
Dimens:: 
Long. 21, lat. 16, apert. long. 11'/3, lat. 9 mm. 
> ROR HAKKÖrnD SME DOP DI RAND v 
VE TN PE RR » 9; » 6 mm. 
Valvata baicalensis GERrRsTF.: testa depressa, superne plana; anfr. supra deplanati, 
parum visibiles, celeriter acerescentes, ultimus septemangulatus; sutura levis; — uncini 
