PLATE II. 



Fig-. 1. Aiicylits (Laii.v) patclloidcs, Lea, (x 1). Pitt River 

 above Copper City. Cal. p. 310. 



Fig. 2. Ancylus fragilis, Tryon. (x 2), San Francisquito 

 Creek, Stanford University, Cal., p. 310. 



Fig. 3. Ancyhis cani)ius, W. Cooper, (x 2), Umpqua River, 

 Elkton, Ore., p. 311. 



Fig. 4. Pompholyx cffiisa, Lea, (x 1), Link River, Klamath 

 Falls, Ore., p. 311. ' 



Fig. 5. Sphcvriuin dcntatuui, Hald., (x 1), Susan Creek, 

 Honey Lake Valley, Cal., p. 305. 



Fig. 6. Vahata Jiumcralis, Say. (x 2), Dewitte, Honey 

 Lake Valley, Cal.. p. 316. 



Fig. 7. Anodoiita cygiica, Linne, (x 1), Dalles, Columbia 

 River, Ore., p. 302. 



Fig. 8. Planorbis opcrculaiis, Gould, (x 2), Mountain Lake, 

 San Francisco, Cal., p. 309. 



Fig. 9. Planorbis opcrciilaris var. ccntcri illciisis, Tryon, 

 (x 2), San Filipe, San Benito Valley, Cal.. p. 310. 



Fig. 10. Planorbis ofcrcularis var. planulatns. Cooper, (x 2), 

 Freeport, Wash., p. 310. 



Fig. 11. Planorbis parzus, Say, (x 1), Artesian Belt near 

 San Jose, Cal.. p. 310. 



Fig. 12. Planorbis opcrciilaris, Gould, (x 2), Mountain Lake, 

 San Francisco, Cal., p. 310. 



