64 THE Ottawa NATURALIST. [June 
Pisidium Idahoense Roper. 
Stewart River, near Mayo River; one dead but perfect speci- 
men and an odd valve. Dr. Sterki writes that the “‘ anterior part 
of the hinge of the former is reversed.”’ 
Pisidium compressum Prime. 
Stewart River, near Mayo River; one specimen. Mr. Mc- 
Innes has recently collected specimens of this species at Ozhiski 
Lake, Attawapiskat River; at Kawinogans River, a branch of the 
Attawapiskat; and at the Winisk River, Keewatin. 
Pistdium variabile Prime, var. 
Stewart River, near Mayo River; two specimens. Mr. Mc- 
Innes has recently collected three specimens on the Kawinogans 
River, which Dr. Sterki has identified with this species. 
Pisidium scutellatum Sterki. 
Frances Lake, fry only;one specimen. Dr. Sterki has recog- 
nized a few specimens of P. scufellatum in collections made by Mr. 
McInnes last year at Ozhiski Lake, and the Kawinogans River, 
Keewatin. 
GASTEROPODA. 
Valvata mergella Westerlund (Dall). 
Stewart River, near Mayo River ; two specimens 
Valvata Lewist Currier (Dall). 
Valvata sincera of Haldeman, C. B. Adams, Dek 
and many subsequent American writers, but, accc 
V. sincera of Say. 
Valvata striata of Lewis, but not of Philippi. 
Frances Lake, ten specimens, and Finlayson 
mens.. Presumably similar specimens were previc 
W. G. Binney, in 1865, under the name V. sz7 
been collected by Major Kennicott from the Pez 
Mackenzie, and Great Slave Lake. Frances and 
both belong to the Upper Mackenzie drainage sys 
Elsewhere in Canada, V. ZLewzs7zz, as recen 
Dall, is now known to occur at many localitie 
Alberta, and as far to the north-eastward as Fort 
