482 LIMN-EID^. 



Foimd from New England to Michigan, and apparently in Cali- 

 fornia. Mr. Lea quotes it from San Antonio Arroya. 



Limnaea humilis. 



Fig. 151. 



Shell ovate, thin, light olive colored; Avhorls four, convex; suture deep; aper- 

 ture rather large, ovate ; fold of columella conspicuous ; sub-umbilicated. 



Limncea humilis, Sat, Journ. A. N. S. ii. 378 (1822) ; Binney's ed. 110. — Haldeman, 



Mon. 41, pi. 13, figs. 1-8 (1842). — De Kay, N. Y. Moll. 71, pi. 4, fig. 71 (1843). 



— W. G. BiNNEY, Smith. Inst. L. and Fr. W. Shells, ii. 63, fig. 99 - 109 (1865). 

 Limnmts morlicella, Say, J. A. N. Sc. v. 122 (1825) ; Binney's ed. 113. — Gould, Inv. 



of Mass. 218, fig. 151 (1841). 

 Limncea Lirtslnji, De Kay, N. Y. Moll. 72, pi. 4, fig. 74 (1843). — Linsley, Shells of 



Conn. Am. Journ. Sc. [i], xlviii. 282 (18-15). 

 Limncea parva, Lea, Proc. Am. Phil. Soc. ii. 33 (1841) ; Tr. ix. 11 (1844) ; Obs. iv. 11. 

 Limncea plica, Lea, Proc. Am. Phil. Soc. ii. 33 (1841) ; Tr. ix. 10 ; Obs. ix. 10 (1844). 

 Limncea Grijfil/tiana, Lea, 1. c. ii.33 (1841) ; ix. 8 (1844) ; Obs. iv. 8. 

 Limncea plunulata. Lea, 1. c. ii. 33 (1841) ; ix. 9 (1844) ; Obs. iv. 9. 

 Limncea rnstica, Lea, 1. c. ii. 33 (1841) ; ix. 10 (1844) ; Obs. iv. 10. 

 Limno'a exiijiia. Lea, 1. c. ii. 33 (1841) ; ix. 9 (1844) ; Obs ix. 10. 

 Limnoia curia, Lea, 1. c. ii. 33 (1841) ; ix. 11 (1844) ; Obs. iv. 11. 



Shell small and short-ovate, very thin and transparent, color a 

 light olive or sea-green ; whorls four or five, convexly rounded 

 and somewhat shouldered or flattened above ; surface rather 

 '^' ' ' coarsely marked by the lines of growth ; anterior whorl 

 large and inflated, two thirds the length of the shell ; pos- 

 terior whorls small ; suture deep ; aperture rather large, 

 somewhat more than half the length of the shell, ovate, or 

 nearly as broad behind as before, not acutely rounded be- 

 hind, but considerably arched ; slightly effuse at base ; columella 

 arched, its fold conspicuous ; inner lip reflected over a small umbil- 

 icus, and the enamel usually broadly spread across to the posterior 

 angle. Length, seven twentieths of an inch ; breadth, four twen- 

 tieths of an inch ; divergence, sixty-eight degrees. 

 Lives along the muddy margins of brooks. 



The animal is of a dark sea-green or bottle-green color above, 

 dotted with amber color ; beneath much paler. Foot long, and in- 

 clining to a point Ijchind. In the region of the eyes, between the 

 tentacula, are clusters of white points, which give an appearance of 

 white eyes. The animal seems to shun immersion, being usually 

 found on the damp mud at the margins of ponds and brooks. 

 When put in a vessel of water it soon rises above the surface, crawls 



