THE CHICAGO ACADEMY OF SCIEX' 



Subgenus SIMPSONIA Nov. Subgen. 



Type: Liwncca humilis S 



Shell: Similar in general form to that of Galba. 



Rabula : With tricuspid lateral teeth. 



Genitalia: Similar to Galba. 



This group of small Lymnaeas is separated from the subgenus 

 Galba mainly on account of the radula. which has tricuspid instead of 

 bicuspid laterals. The shell offers no definite characters of group value 

 bv which to separate Simpsonia from Galba. The subgenus contains 

 the humilis-obrussa-parua group of Lymnaeas, in which the shell is 

 usually small and without marked spiral sculpture. It is mainly con- 

 fined to the northern part of the United States and Canada. 



Galba umbilicata (C. B. Adams). Plate XXX, figures 1-7. 



LimncEa umbilicata C. B Adams, Amer. Journ. Sci., i. XXXIX, p. 374, 

 1840. — Bost. Journ. Xat. Hist., Ill, p. 325, pi. iii, fig. 14, 1840.— Taylor and 

 Shiverick, Cat. 1840. — Gould. Invert. Mass.. p. 218, fig. 149, 1841. — Prescott, 

 Cat. Sh. Mass., Xo. 198, 1842. — Reed, Cat., 1845. — Russell, Journ. Essex Co. 

 Xat. Hist. Soc, p. 130, 1852.— Lewis, Proc. Bos. Soc. X. H. VI. p. 2, 1856 

 (part). — Tufts, Proc. Essex Institute. I, p. 30, 1856. — True, Proc. Essex Inst., 



II, p. 195. 1857.— Whiteayes, Can. Xat.. VIII, p. 103, 1863. — Bixxey, L. & F. W. 

 Sh. X. Am, II, p. 57, fig. 88, 1865. — Gould, Bixxey Ed., Inv. Mass.. p. 480, 

 fig. 731, 1870. — Jeffreys, Ann. Mag. X. H., ser. IV, X, p. 247, 1872 (part) ; 

 Journ. Conch., I, p. 8, 1874 (part). — H. F. Carpexter, Random Xotes, III, p. 86, 

 1886.— Pilsbry, Proc. Phil. Acad., p. 320, 1891. 



Lymncra umbilicata Lea, Journ. Phil. Acad., VI, pp. 161, 162, 1866; Obs., 

 XI. pp. 117. 118, 1867. — Scudder, Bull. Xat. Mus., 23, p. 201, 1885. — Walker. 

 Nautilus, XXII, pp. 7, 8, figure 1, pi. 2. figs. 1. 2, 1908: Ottawa Xat.. XXII, pp. 

 90-91, fig. 3, 1908. — Lermoxd, Shells of Maine, p. 37, 1909. — Baker, Xautilus, 

 XXIII, p. 80, 1909. 



Lymncea caperata var. umbilicata Jay, Cat. Ed. 4, p. 268, 1S52. 



Limnea umbilicata Hald., Mon. Limn., p. 34, pi. 11, fig. 9, 1842. 



Limneus umbilicatus Clessix, Mai. Blatt., n. s., Ill, p. S3, 1S81. 



Limnaa umbilicata Jacksox, Xautilus, XXI. p. 142, 190S. 



Limncca humilis Herox*. Ottawa Xat, I, p. 39, 1880. — Xylaxder. Xautilus, 

 VIII, p. 126, 1S95; XIII, p. 104, 1900.— Lermoxd, Shells of Maine, p. 38, 1908 

 (part). 



Lymnca grifiithiana Lea, Proc. Amer. Phil. Soc, II, p. 33, 1841; Trans. 

 Amer. Phil. Soc, IX, p. 8, 1S44; Obs., IV, p. 8, 1848. 



Lymnaa grifiithiana Wheatley, Cat. Sh. U. S., Ed. 2, p. 23. 1845. — Scud- 

 der, Bull. Xat. Mus., 23, pp. 43, 201, 1885. 



Limncca grifiithiana Bixxey, Check List, p. 12, 1860; Land and F. W. Sh. 

 X. A., II, p. 66, fig. 107, 1865.— Tryox, Amer. Journ. Conch., Ill, p. 196, 1867; 

 Con. Hald, Mon., p. 105 (79), pi. 18, fig. 5, 1S72.— Clessix, Mai. Blatt., n. s. 



III, p. 81, 1881. 



Limnaa cubensis Crosse & Fischer, Pilsbry. Vox* M.artexs. etc. (not 

 Pfr.). 



