I I I THE CHICAGO ACADEMY OF SCIENCES. 



Limnasa bulimoides var. apicina Cooper, Proc. Cal. Acad. Sci., IV, p. 96, 

 1870. 



Limnea catascopium Hald., Mon. Limn., p. 8, pi. 1, fig. 9, 1842; Mon. Lim., 

 p. 52, pi. 14, fig. 5, 1842. 



Limncca catascopium? Binney, L. & F.-W. Sh. N. A., II, p. 50, fig. 86, 

 1865. 



Lymncca catascopium Baker, Trans. Acad. Sci. St. Louis, XVI, p. 13, 1906. 



Limncea decollata Binney, L. & F.-W. Sh. N. A., II, p. 32, 1865 (part).— 

 Currier, Kent. Sci. Inst., Mis. Pub., No. 1, 1865.— Dawson, British N. A. Bound. 

 Com., p. 349, 1875. — Walker, Journ. Conch., II, p. 330, 1879. — Christy, Journ. 

 Conch., IV, p. 347, 1885.— Walker, Nautilus, VI, p. 32, 1892 ; Rev. Moll. Mich., 

 1894, p. 17.— Hanham, Nautilus, XIII, p. 5, 1899 ( ?).— Ruthven, Rep. Mich. 

 Acad. Sci., VI, p. 190, 1904; Rep. Geol. Surv. Mich., 1905, pp. 23, 24, 35, 95, 

 1906. 



Radix decollata DeCamp, Kent. Sci. Inst., Mis. Pub., No. 5, p. 7, 1881. 



Limncea brownii Tryon, Amer. Journ. Conch., Ill, p. 196, 1867 (part). 



Limncza solida Tryon, Con. Hald. Mon., pp. 107 (81), 111 (85), 1872. 



Limnea solida Hald., Mon. Limn., p. 38, pi. 11, fig. 12, 1842. 



Shell : Globose or ovate, inflated, generally rather solid ; perios- 

 tracum pale horn, darker in some specimens ; surface shining, almost 

 polished, lines of growth coarse and close-set, spiral striation pro- 

 nounced ; nuclear whorls wine-colored, in outline resembling those of 

 binneyi; whorls 4-5, rapidly increasing in size, inflated, tumid ; spire 

 short, generally very broad, dome-shaped, frequently much depressed; 

 sutures impressed, frequently bordered by a white band ; aperture ovate 

 or roundly ovate, occupying usually more than half the length of the 

 shell ; outer lip very convex, with an internal transverse varix, edged 

 with brown ; inner lip triangular, rather narrow, tightly appressed to 

 the umbilical region, leaving a very small chink; parietal callus very 

 thin ; axis twisted forming a distinct ascending plait. 



Length. 



Width. 



Aperture length. 



Width. 





10.25 



7.25 



6.25 



3.50 mill. 



Type apicina. 



9.50 



7.00 



6.50 



3.50 " 



" " 



12.00 



9.00 



8.50 



4.50 " 



Lake Superior. 



12.80 



10.00 



9.00 



5.00 " 



" " 



15.00 



9.00 



9.00 



5.00 " 



" " 



16.25 



10.25 



10.50 



5.75 " 



" " 



15.50 



11.00 



10.50 



6.50 " 



" " 



12.50 



9.00 



8.50 



5.00 " 



Union River, Mich. 



14.00 



10.00 



9.00 



5.50 " 



Menominee River, Mich. 



14.00 



10.50 



9.50 



6.00 " 



" " " 



15.50 



12.25 



11.00 



6.75 ■ 



Iron Co., Mich. 



16.00 



11.10 



10.00 



6.25 " 



Twin Falls, Mich.. 



18.50 



14.00 



13.00 



7.10 " 



" " " 



18.00 



11.00 



10.00 



5.50 " 



(Oregon.) 



15.00 



11.00 







(Lake of the Woods, Daw- 

 son.) 



