4S 
Pisidium sen tella turn Sterki 
Bamaji, Hamilton, Pashkokogan, and Kimmewin lakes. Reported 
from Kawinogans river and Ozhiski lake by Whiteaves. Mackenzie 
river and Yukon territory (Whiteaves and AVhittaker). Rarely recorded 
from Canadian localities. Dr. Sterki has shown that his scutellatum is 
probably the same as the European lilljeborgi of Clessin, but as the varieties 
of that species in Europe are little known it appears best, as suggested by 
Sterki, to use the American name for our own species. The Canadian 
forms are somewhat different from the species as known farther south. 
Pisidium sp. inclet. 
Some material from Bamaji and Botsford lakes is at present indeter- 
minable. Dr. Sterki says that the Kcewatin (northern Ontario) material 
contains a number of peculiar forms and suggests that future collecting 
may bring to light many additional peculiar varieties and species. This 
area should be almost virgin territory for students of the Sphaeriidae. 
Many species of Pisidium not collected by the Cahn party are recorded 
from this territory. Whiteaves has listed the following: 
Pisidium fctllax septentriouale Sterki (= errnns Sterki) — Ozhiski lake, Knee lake, 
Hayes river 
Pisidium sargenli Sterki — -Kawinogans river 
Pisidium spleudidulum Sterki — Ozhiski lake; lake St. Joseph 
Pisidium politum Sterki — Ozhiski lake; Root river 
Pisidium uiaimnsc Sterki- — Root river 
Pisidium abdifum Haiti.— -Albany river 
Pisidium roperi Sterki — Albany river 
Pisidium paupercidum crystaUense Sterki— Root river 
Pisidium vesiculare Sterki — Head of lake St. Joseph 
Pisidium milium Haiti. — Head of lake St. Joseph 
Pisidium v:alkeri Sterki — Attavvapiskat river 
From Manitoba the following species are known, any or all of which 
are likely to be found in northern Ontario: 
Pisidium medianum Sterki Pisidium paupercidum Sterki 
Pisidium ventricosum Prime Pisidium lennissimum Sterki 
Pisidium noveboracense Prime Pisidium subrotundum Sterki 
Family, Valvatidak 
Valvata tricarinata (Say) 
Outlet of lake Bamaji; Fitchie, Kimmewin, Botsford, and Cat lakes. 
Mostly strongly carinate and hence typical. The material from Cat lake 
has a much depressed spire and is sharply tricarinate. It would be of 
interest to know how general this variation is among the Valvatidae of 
the northern lakes. This species is reported by Whiteaves from Sutton 
lake, lake St. Joseph, Kawinogans and Attawapiskat rivers, and Albany 
river. Dali records it from Moose Factory and the variety simplex Gould 
from English river. It is abundant in Manitoba and Whittaker found it in 
Mackenzie River district. 
Valvata tricarinata perconfusa Walker 
Outlet Bamaji lake, abundant and very variable as regards distinctness 
of the two carinse. This variation has not generally been recognized by 
Canadian writers. Mackenzie River material examined was all referable 
to the typical form. 
