THE NAUTILUS. 65 



shallow. Here we found Planorbis trivolvis, P. bicarinatus, Limncea 

 desidiosa and Goniobasis livescens. Among the latter there were 

 many which connected livescens with depygis, having well marked 

 color bands and a purple timed 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 

 Kiver). Limncea 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. refl.exa. The stream was very rapid, and Lim- 

 ncea 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 L. 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 Limncea palustris, L. caperata, L. humilis, Planorbis trivolvis, 

 P. bicarinatus, Aplexa hypnorum and Physa heterostroplia. 



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, cyliadrica, parva, oleacea and soyii. 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 SPH.ZER1UM. 



BY F. C. BAKER. 



Sphaerium lilycashense sp. nov. 



Shell differing from typical striatimim in being larger, more reg- 

 ularly oval, much more inflated and with the umbones more inflated 



