868 i HE CHICAGO ACADEMY <'F SCIENI ES. 



Smithsonian collection, is a form of modicclla. The cotype has a 

 narrow reflection of the inner lip which leaves a rather small umbilical 

 chink. A comparison of the figure on plate XXXI, which is a photo- 

 graph of the cotype, with Tryon's figure •'!, plate. 18, of his continu- 

 ation of Haldeman's Monograph, will serve to show how little depend- 

 ence can be placed upon a figure made by the ordinary artist in correctly 

 depicting the shells of mollusks. 



Galba humilis rustica (Lea). Plate XXXI, figures 10-14. 



Lymnea rustica Lea, Proc. Amer. Phil. Soc, II. p. 33, 1841; Trans. Amer. 

 Phil. Soc, IX, p. 10, 1844; Obs., IV, p. 10, 1848.— Scudder, Bull. Xat. Mus., 23, 

 pp. 33, 44, 201, 1885. 



Lymncca rustica Wheatley, Cat. Sh. U. S.. p. 23, 1843. 



Limncca rustica Binney, Check List, p. 12, 1860; L. & F.-W. Sh. X. A.. 

 II. p. 65, fig. 106, 1865.— Clessin, Mai. Blatt, n. s„ III, p. 81,- 1881.— Ckll., Ann. 

 Mag. N. H., Ser. 5, XIX, p. 176, 1887. 



Shell : Small, elongated, subf usiform ; periostracum light yellow- 

 ish horn, darker in some specimens ; surface shining, growth lines 

 coarse, spiral lines absent or very faint; whorls 5 to o J /2, convex, rather 

 slowly increasing in diameter, the body whorl suddenly enlarging; 

 spire long, very acute, generally a trifle longer than the aperture ; 

 nuclear whorls resembling those of modicclla; sutures impressed; 

 aperture usually narrowly elliptical ; outer lip thin, sometimes with a 

 varix ; inner lip narrow, reflected, the lower part turned up, the upper 

 part at its junction with the parietal wall impressed and flattened, 

 forming a slight plait ; umbilical chink usually very narrow, in some 

 specimens nearly closed; axis as in modicclla. 



Length. 



Breadth. 



Aperture length. 



Breadth. 





7.50 



4.00 



3.75 



1.50 



mill. 



Smithsonian specimen 



8.75 



4.00 



4.50 



2.10 





Mohawk, X. Y. 



8.50 



4.00 



4.00 



2.00 



" 



" " 



9.75 



4.50 



5.00 



2.50 



" 



Albuquerque, X. M. 



10.50 



4.75 



5.50 



2.50 



" 





8.50 



4.00 



4.00 



2.00 



" 



.i a 



7.75 



4.00 



4.00 



2.00 



" 



Joliet, 111. 



8.50 



4.25 



4.50 



2.25 



" 



" " 



9.75 



4.75 



4.90 



2.25 



" 



Alpena, Mich. 



9.00 



4.00 



4.00 



2.50 



" 



Cedar Lake, Mich. 



10.00 



4.80 



4.50 



2.50 



" 



" " 



Types : 



Not in 



existence ; autotype, 



one 



specimen. Smith. Ir 



No. 118652. 













Type Locality : 



Poland, Ohio. 









Animal: Not differing externally from modicclla. 

 Jaw : As in modicclla. 



