,24 a 



July 4. 



May 15. 



August 14. 



1916. 

 July 29- 

 August 2. 



1914. 

 May 28. 



9116., 

 July 26. 



1915. 

 June 26. 

 1916. 

 April. 

 1915. 

 June 28. 

 Aug. 6. 



June 28. 

 August 16. 



September 1. 



October 1- 

 Dec. 20. 



1916. 

 May 6. 



June 23-24. 

 July 5. 



Canadian Arctic Expedition, 1913-18 



Alaskan Arctic coast. The species is the same as those from 

 Nome, Alaska, and the one from Bernard harbour, N.W.T. 



Konganevik, Camden Bay, Alaska: On the coastal tundra 

 near the sea was a pond with rich vegetation and a broad fringe of 

 washed-up plant debris at its edge. On this fringe were many 

 empty shells of the common fresh- water snail (Aplexa). 



Demarcation point, Alaskan Arctic Coast: Creeping over the 

 mud-bottom of a just melted pond on the poastal tundra were a 

 couple of Aplexa, the common fresh-water snails. 



Herschel island, Yukon Territory, Arctic Canada: In a pond 

 (not the same as 1916, but both ponds about 100 feet elevation) 

 situated inland on the east end of the island, I collected many 1 to 

 8 mm. long, brown Aplexa. 



Same locality (Herschel island) : In a pond (not the same as 

 1914, but both ponds at about 100 feet elevation) situated on the 

 tundra swamp inland at the east end of the island, I collected 

 several fresh water snails (Aplexa) among the dense growth of 

 Hippuris, etc. 



Iglukitaktok, West branch of Mackenzie Delta (68° 20' lat. N., 

 135° 26' long. W.) : J. J. O'Neill collected Lymnoea appressa floating 

 in the fresh water flooding the ice, near the marshy margin of a 

 small lake. 



Cape Bathurst, Northwest Territories, Canada: The common 

 fresh water snails (Aplexa) collected in waterholes in the tundra 

 back of the sandspit. 



Bernard ha,rbour. Northwest Territories, Canada: Lake trout 

 (Cristivomer namaycush W.) caught by Eskimo in lakes around 

 here had in their stomachs about 1 dozen 2-5 mm. cla,ms. The 

 youngest clams had the shell pure white; the older ones had this 

 greyish (Pisidium rotundatum) . In the different larger ponds I 

 found the shallow-water snails (Aplexa) attached to the grass 

 stems or as empty shells on the mud-bottom. Shell brown; pro- 

 truding, soft body-part grey; head almost black. 



Bernard harbour: From stomach of lake-trout, caught as 

 June 26, 1 snail (Lymnoea vahli) and many Pisidium rotundatum. 



Under a stone on moist ground (tundra) inland, I found a 15 

 mm. long brown, naked Pulmonate snail (Agriolimax) . Dorsal 

 side (especially mantle-shield, tentacles and their base, and body 

 back of the mantle) black-brown, getting Hghter brown laterally, 

 until the whitish (grey) footsole is reached. The rainy weather 

 these days has probably brought this snail out from its hiding place. 

 Ihis IS the first and only naked snail I have found east of Mackenzie 

 delta. 



Fungus (Agaricus?) found gnawed by snails. 

 ^uH *1°^*, ('^«^«'e'wws marstoni) caught by us in the big lake 

 south of the harbour, often had in their stomachs many of' the 

 common small fresh-water clams (Pisidium). 



Same locality (Bernard Harbour) : A few Pisidium from bottom 

 ot big lake south of harbour were collected, 

 of ththarbouT^*^'" ^""^^^ (^P^«^«) collected in the big lake south 



Many of the common fresh-water snails (Aplexa) and a few 

 Lymnceamd Physa were collected in the shallow bights at the outlet 

 ot the big creek from the big lake in valley back of the harbour. 

 Vnh^f ^f'P^y.f^^^^ Lym.nma vahli and Aplexa hypnorum and 

 Valvata lewisii found washed up at the mouth of another big creek 



