: seeeciaiaal 
THE NAUTILUS. 
Vol. XXXII JANUARY, 1920. No. 3. 
GONIOBASES OF OHIO. 
BY CALVIN GOODRICH. 
Some months ago I had occasion to map the known distribu- 
tion of Goniobasis livescens Menke and G. semicarinata Say within 
the borders of Ohio. This distribution is somewhat peculiar. 
Beginning on the western side of the state above the central 
line we find that livescens is the Goniobasis of the Maumee river 
system and of the shallows of Lake Erie as far as Sandusky 
Bay, where G. haldemanni occurs in company with livescens in 
the drift of the beaches. So far as exploration thence east 
shows, livescens appears alone to the northeastern corner of 
Ohio. © It is the species of Sandusky River, flowing into San- 
dusky Bay, of Rocky and Cuyahoga Rivers which enter the 
lake at Cleveland, and of Conneaut Creek near the eastern 
border. Below the divide between the lakes and the Ohio River 
drainages, I found livescens in Beaver Creek, a tributary of the 
Wabash. There is then a great gap in its occurrence until the 
Hocking River is reached, east of a north and south central line 
drawn through the state. Just east of this, again, livescens has 
been collected in the Tuscarawas River of the Muskingum sys- 
tem by Dr. Sterki, and in at least one of the Tuscarawas 
branches. The G. gracilor Anth. of the Summit county lakes 
is plainly an offshoot of livescens, as indicated by connecting 
forms taken in this same region. 
Goniobasis semicarinata, less variable and more easily recog- 
nizable even in the field than livescens, is the species of the 
Great Miami, Little Miami and the Scioto Rivers, all in the 
