248 THE CHICAGO ACADEMY OF SCIENCES. 



collection of several thousand specimens of parva-\-curta, sent for 

 examination by Mr. T. Van Hyning of Des Moines, Iowa, proves 

 beyond a question that the two forms are the same species. The 

 statement in the Nautilus (XXIX, p. 52, 1905) is erroneous, the speci- 

 mens there considered parva being a totally distinct species. (See 

 dalli, page 251.) Limncea tazewelliana, described from Pleistocene 

 deposits of the Illinois River, is undoubtedly the same as parva. Speci- 

 mens from Des Moines, identified as tazewelliana by Dr. Pilsbry, are 

 the same as Lea's parva in the Smithsonian collection, and the figure 

 and description of tazewelliana agree perfectly with the Des Moines 

 specimens. Wolf's figure is probably too obese in the body whorl, 

 however. The type of tazewelliana was thought to be in the Phila- 

 delphia Academy, but a careful search failed to reveal it in the col- 

 lection. The Wolf collection was presented to the high school at 

 Canton, Illinois, but efforts to secure information concerning Wolf's 

 types were fruitless. 



Galba parva sterkii (Baker). Plate XXIX, figures 15-22. 



Lymnaa sterkii BAKER, Nautilus, XIX, p. 51, Sept. 1905; Bull. 111. State Lab. 

 N. H., VII, p. 104, 1906. STERKI, Proc. Ohio State Acad. Sci., IV, p. 382, 1907. 

 DANIELS, Nautilus, XXII, p. 121, 1909. 



Lymncea parva sterkii BAKER, Bull. 111. State Lab: N. H., VIII, p. 492, pi. 25, 

 fig. 21, 1910. 



SHELL : Small, elongated, turreted, rather thin ; color light yellow- 

 ish horn, darker in some specimens ; surface dull to shining, marked 

 by distinct, crowded, raised growth lines generally without spiral lines ; 

 nucleus small, rounded, about the same size and shape as that of parva; 

 whorls 5J/2-6, very convex, somewhat shouldered, especially the last ; 

 spire narrow, rather acute, turreted, generally longer than the aperture, 

 sutures very deeply impressed; aperture ovate, much expanded an- 

 teriorly; outer lip sharp, thin; inner lip forming a very broad, flatly 

 concave expansion reflected over the umbilicus, which it emargins; 

 there is a thin wash of callus on the parietal wall; umbilical chink 

 narrow but deep; axis thickened, straight. 



Length. Breadth. Aperture length. Breadth. 



7.75 3.50 3.50 1.75 mill. Type 



7.75 4.00 3.25 2.00 " 



8.00 3.50 3.50 2.00 " " 



7.00 3.50 3.25 2.00 " 



10.00 4.75 4.75 2.50 " Canton, 111. 



9.00 4.50 4.60 3.00 " 



TYPES: The Chicago Academy of Sciences, five specimens, Nos. 

 23155, 23156; cotypes, Philadelphia Academy of Sciences, No. 90177; 

 coll. Sterki. 



