398 THE CHICAGO ACADEMY OF SCIENCES. 



nasoni, but that species is larger, has a more regularly globose shell, 

 a longer spire and broader inner lip which emargins the umbilical 

 chink. Nasoni belongs to the catasc opium group, while apicina is a 

 member of the emarginata group. 



The species is named in honor of Dr. William A. Nason, of 

 Alongquin, Illinois, who collected the specimens. 



Galba woodruffi (Baker). Plate XLII, figures 18-22. 

 Limncea catascopium pinguis BAKER (non Say), Trans. Acad. Sci.; St. 

 Lduis, XI, p. 5, pi. 1, fig. 12, 1901. 



Limnaa woodruffi BAITER, Bull. Chi. Acad. Sci., II, p. 229, fig. 1901 ; Moll. 

 Chi. Area, II, p. 264, pi. 31, fig. 8, 1902. BLATCHLEY & DANIELS, An. Rep. Dept. 

 Geol. & Nat. Res., Ind., XXVJI, p. 598, pi. 1, fig. 16, 1902. DANIELS, 1. c., 

 p. 636> 1902. CKLL., Nautilus, XVI, p. 96, 1902. 



Lymnaa woodruffi BAKER, Bull. 111. State Lab. N. H., VII, p. 104, 1906. 

 SHELL: Small, ventricose, inflated, rather solid; periostracum 

 greenish-horn or olivaceous; surface shining, growth lines crowded, 

 very distinct, crossed by fine impressed spiral lines; nuclear whorls 

 roundly inflated, light or dark horn colored similar in outline to those 

 of jacksonensis; whorls 4-4^, convex, tumid, the body whorl very large, 

 occupying more than two-thirds the length of the shell ; spire generally 

 much depressed, globose ; sutures well impressed ; aperture very large, 

 long-ovate to roundly ovate, broadly rounded below, angulated above, 

 occupying about two- thirds the total length of the shell; it is some- 

 times shouldered ; outer lip thickened within by a heavy longitudinal va- 

 rix ; inner lip rather wide, with parallel margins, spreading over the um- 

 bilicus which it slightly emargins and forming a wide, flattened ex- 

 pansion ; an umbilical chink is usually present ; the callus on the parietal 

 wall is thick and heavy and is the same width as the inner lip; in 

 some specimens the columella is thickened in the middle forming a 

 distinct tubercle; a columellar plait is not developed, but the axis, 

 especially in the upper whorls, is distinctly twisted. 



Length. Width. Aperture length. Width. , 



11.80 8.50 8.50 5.50 mill. Type. 



10.50 7.25 8.50 4.75 " 



10.50 7.00 8.00 5.00 " 



9.00 5.25 6.00 3.50 " Millers. 



9.50 6.00 6.75 3.50 " " 



13.?5 8.00 9.50 4.50 " Chicago. 



11.50 7.50 8.25 4.25 " " 



TYPES: Five specimens, Chicago Academy of Sciences, 23789 

 and 3425. 



TYPE LOCALITY : Lake Michigan, Oak Street, Chicago, Illinois. 

 ANIMAL, JAW, RADULA and GENITALIA: Unknown. 



