. ECOLOGY OP NORTHERN MICHIGAN. 95 



22. Euconulus chersinus polygyratus (Pils.). II. 2. Among the damp 

 leaves in the hardwood forest. III. 1. Under fallen logs in the aspen zone 

 about the mountain top. III. 2. In the dry soil in rock crevices and among 

 grass roots near the brink of the precipice. VI. In the loam on the bank 

 of Carp creek. 



23. Succinea avara Say. III. 2. A few shells were found in crevices in 

 the rock on the brink of the cliff. These specimens were probably blown 

 here as the animal is said to prefer a damp habitat. / 



24. Carychium exile H. C. Lea. II. 2. Several individuals of this form 

 were taken in a very moist place among fallen leaves in the hardwood forest. 

 Also found in very wet humus about the roots of ferns on the banks of Carp 

 creek, VI. 



25. Limnaea decollate/, Migh. Occurs quite frequently in the rock pools 

 of the Middle Beach, and behind projecting outcropgon the Lower Beach of 

 Lake Superior, I, where they were protected from the full force of the waves. 



26. Limnaea desidiosa Say. I. Occurs quite numerously in the rock 

 pools of the Middle Beach, and has been dredged in Lake Superior at a depth 

 of 8 to 13 fathoms (Baker). 



27. Physa sp. (too young to identify). IV. 1. Found on the under 

 side of lily pads in Carp river. 



28. Physa sayii? Tapp. (young specimen). VI. Found in very damp 

 leaves on the bank of Carp creek. 



29. Physa ancillaria Say. var. I. In the rock pools of the Middle 

 Beach of Lake Superior. 



30. Planorbis campanulatus Say. Taken on the under side of lily pads 

 and among the leaves of submerged water plants on Carp river, IV. 1, and 

 on the larger stones forming the bottom near the shore of Carp Lake, V. 1. 



31. Planorbis bicarinatus striatus Baker. V. 1. Found on the stones 

 composing a strip of shingle beach on Carp Lake. 



32. Planorbis exacuous Say. IV. 1. Taken on the under side of water 

 lily leaves in Carp river. 



33. Planorbis parvus Say. I. This species was found in several of the 

 pools on the Middle Beach of Lake Superior, both on the bare rock and in 

 the slight algal growth that lines the sides. It was also found among the 

 leaves in the bottom of a pool formed by a spring in the forest, II. 2, and in 

 considerable abundance on the under side of the larger rocks that lie loosely 

 in the bed of Carp creek, VI. Dredged in Lake Superior at a depth of 8-13 

 fathoms (Baker). 



34. Planorbis deftectus? Say. (immature). V. 1. Found on the small 

 stones forming the bottom of Carp Lake just off shore. VII. 3. On the 

 submerged sticks of a beaver dam on Little Carp river. 



35. Planorbis hirsutus Old. IV. 1. Among the leaves of a submerged 

 aquatic plant in Carp river, about two feet below the surface of the water. 



36. Ancylus parallelus Hald. IV. 1. On the stems and under side of 

 lily pads in Carp river. 



37. Valvata tricarinata (Say). V. 3. Among the leaves of submerged 

 aquatic plants in Carp Lake. 



38. Amnicola limosa (Say). IV. 1. Abundant on the stems and under 

 side of lily pads, and among the leaves of submerged aquatics in Carp river. 

 Also common on the stems and among the leaves of submerged aquatic 



. plants in Carp Lake, V. 3. 



39. Anodonta marginata Say. V. 1. Occurs quite numerously in Carp 

 Lake, just off shore on a bottom of either silt or pebbles, and in considerable 



