LYMN^ELLXE OF NORTH AMERICA. 171 



thirds the size of the more northern forms. Typical specimens of 

 this small form, which does not seem important enough to receive a 

 name, measure as follows : 



Length. Breadth. Aperture length. Breadth. 

 10.00 6.50 7.00 4.50 Mill. Manatee Co., Fla. 



12.00 7.50 9.00 6.00 " Pass Christian, Miss. 



All of the Succinea-like Lymnaeas have been united with columella 

 by most recent authors, but there are strong reasons for admitting 

 several varieties. It was thought at one time that two distinct species 

 could be recognized, but the large amount of material examined shows 

 so many connecting links that a satisfactory specific diagnosis is im- 

 possible. There are three fairly well marked varieties, however, which 

 should be recognized. 



Say's macrostoma cannot be separated- from columella when a 

 large series of specimens is examined. As Haldeman remarks, it is 

 a columella until it assumes the macrostomous form in the large ex- 

 panded body whorl, which in typical macrostoma is flaring and quite 

 patulous. The figures on the plate well illustrate the variation in the 

 body whorl. (PI. XXIII, figs. 8, 10, 11, for example.) Von Martens 

 questions the Mexican reference to this species in the Biologia Centrali 

 Americana, but the records of Cooper and Rhoads confirm its concur- 

 rence in Mexico. These records, however, should probably be referred 

 to the race called championi. 



Pseudosuccinea columella chalybea (Gould). Plate XXIV, 

 figures 5-13. 



Limnaa chalybea A. A. GOULD, Amer. Journ. Sci., XXXVIII, p. 196, 1840. 

 GOULD, Invert., Ed. Binney, p. 472, 1870. SOWB., Conch. Icon., XVIII, Limn., 

 sp. 52, pi. 8, fig. 52, ,a. b., 1872. 



Limnca chalybea HALD., Mon. Limn., p. 40, pi. 12, fig. 9, 1842. ANTHONY, 

 L. F-W. Sh. Cin., Ed. 2, 1848. GOULD, Otia, p. 180, 1862. 



Lymnaa chalybea LINSLEY, Amer. Journ. Sci., XLVIII, p. 282, 1845 

 WHEATLEY, Cat. U. S. Shells, p. 23, 1845. MORSE, Amer. Nat. Ill, pi. 11, fig. 18, 

 1870. 27 Ann. Rep. N. Y. State Mus., p. 53, 1875. 



Limnea columella var. chalybea MIGHELS, Bost. Journ. N. H., IV, p. 336, 

 1843. GOULD, Invert. Mass., p. 210, fig. 149, 1841. PRESCOTT, Sh. Mass., No. 192, 

 1842. READ, Cat., 1845. Can. Nat. & Geol., II, p. 197, figure, 1857. BINNEY, 

 Land & F. W. Sh. N. A., II, p. 34, fig. 40, 1865. JAY, Cat. Ed. 4, p. 268, 1852. 



Lymncea columella chalybea BAKER, Bull. 111. Lab. N. H., VII, p. 103, 1906. 

 STERKI, Proc. Ohio State Acad. Sci., IV, p. 382, 1907. HANNA, Nautilus, XXIII, 

 p. 96, 1909. 



Lymnaa columella var chalybea LERMOND, Shells of Maine, p. 37, 1908. 



Lymnea strigosa LEA, Proc. Amer. Phil. Soc., II, p. 33, 1841 ; Trans. Amer. 

 Phil. Soc., IX. p. 12, 1844; Obs., IV, p. 12, 1848. 



Lymn&a strigosa WHEATLEY, Cat. U. S. Shells, p. 23, 1845. MORSE, Amer. 

 Nat., Ill, pi. 11, fig. 19, 1870. SCUDDER, Bull. Nat. Mus., 23, pp. 33, 44, 201, 1885. 



