THE NAUTILUS. 65 
shallow. Here we found Planorbis trivolvis, P. bicarinatus, Limnea 
desidiosa and Gioniobasis livescens. Among the latter there were 
many which connected Jlivescens with depygis, having well marked 
color bands and a purple tinted columella. 
The last stop was made at Lockport where the train waited over 
an hour, and while the majority of the party studied the bear trap 
dam, the conchologists “pocketed” their cans and bottles and 
climbed (or fell) to a good sized creek (a branch of the Desplaines 
River). Limnea palustris was here so abundant that it could be 
collected by the quart, and they were all large, fine specimens. 
Many specimens were very long and pointed and seemed to show a 
tendency toward L. refleca. The stream was very rapid, and Lim- 
nea and Planorbis seemed to be the only genera able to live in any 
numbers. Physa was abundant dead, but only three or four living 
specimens could be found. It decidedly prefers still water in this 
region. A single specimen of ZL. palustris was found in which the 
base had suffered some injury, and the aperture was thrown off to 
the right, leaving a wide and deep false umbilicus. We collected 
here Limnea palustris, L. caperata, L. humilis, Planorbis trivolvis, 
P. bicarinatus, Aplexa hypnorum and Physa heterostropha. 
Physa heterostropha at this locality shows a wide range of varia- 
tion. Some are long and cylindrical, others broad and stumpy, and 
the spire runs from obtuse to pointed. The number of whorls was 
invariably the same. In this lot one could easily pick out such 
pseudo species as gyrina, cylindrica, parva, oleacea and sayti. The 
writer has recently tried Crosse and Fischer’s suggestion in regard to 
specific characters in the form of the teeth on the radula, but thus 
far with a decidedly negative result. 
The results of the field day, conchologically, may be summed up 
as follows: Pleistocene species 8, recent species 19. We carried 
home several quarts of mollusks. 
A NEW SPHERIUM. 
BY F. CajBAKER-. 
Spherium lilycashense sp. nov. 
Shell differing from typical striatinum in being larger, more reg- 
ularly oval, much more inflated and with the umbones more inflated 
