62 C GEOLOGICAL SURVEY OP CANADA. 



14. Limncea stagnalis, Linne\ Lake Winnipeg, Nelson Kiver and lakes 



and rivers to the south-eastward. 



15. Linnophysa catascopium. Say. Great Playgreen Lake. 



16. Physa heterostropha, Say. Inhabits the same waters as Limncea 



stagnalis. 



17. JBulinus hypnoruin, Linne". 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. 



