G2 c 



GEOLOGICAL SURVEY OF CANADA. 



14. Limncea stagnalis, Linn^. Lake Winnipeg, Nelson Elver and lakes 



and rivers to the south-eastward. 



15. Linnophysa catascopium, Say. Great Playgreen Lake. 



16. Physa hete?'Ostropha, Say. Inhabits the same waters as Limncea 



stagnalis. 



17. Bulinus hypnorum, Linnd. Ponds in Manitoba. 



18. Helisoma trivolvis, Say. Around Winnipeg and in Manitoba. 



19. Helisoma bicarinatus, Say. Lake Winnipeg. 



20. Segmentina armigera, Say. Abundant in Great Playgreen Lake. 



