14 THE AMERICAN MIDLAND NATURALIST 
for O. olivaria, although the largest shells of this species were 
obtained at Wabasha. A. corpulenta of the river at this 
point seems to be much thicker than the same species as ob- 
tained from the sloughs. Locality I-2 is known to old time 
clammers as the Trenton Bed. While still fairly productive, 
no clammers were observed working it at this time. Juveniles 
were comparatively rare in this area. 
AREA II. 
Boundaries, Red Wing, Minn., to Bay City, Wis. Status, 
closed to fishery. Length in Linear Miles, 5.8. Physical 
Conditions, 7 ft. high water; current about 3 miles per hour; 
bottom mostly sand and mud; snags most abundant toward 
the Wisconsin shore. Water weed in lower stretches. 
LOCALITIES REPORTED UPON. (ref. maps.) 
II—1. Starting point of drags 300 ft. upstream off Wis- 
consin shore from Govt. Day Mark 958-e, on edge of main 
channel about 40 ft. from shore. July 10, 1920. 
II—2. Starting point of drags 35 ft. from shore, about 
4, mile downstream from Govt. Day Mark 958-d, opposite 
bathing houses and summer camp on Minn. shore. July 10, 
1920. 
II—4. Starting point of drags 100 ft. downstream from 
Govt. Day Mark 958-b, 45 ft. from Minnesota shore. 
NOTES ON AREA. 
Collecting in this area was best on the edge of the channel. 
It was extensively clammed some years ago. At present, 
there appear to be fewer shells of the Quadrula group than 
others. Truncilla triquetra was first recorded frorc the 
upper region of the river at this point. Juveniles, especially 
of Anodonta and Lampsilis sp. are more abundant here than 
in the preceding area. 
