lymn^eim: of north America. 149 



of typical stagnalis. The spire is also more regular in form, that of 

 stagnalis having a more or less pinched-in appearance. 



Prof. Cockerell has suggested (Nautilus, XVI, p. 96) that the 

 American shells might be included in the Helix fragilis of Linne. After 

 an examination of European and American specimens, I am not in- 

 clined to adopt this course, particularly as the English conchologists 

 consider the fragilis to be a smaller form than appressa. The descrip- 

 tion of Linne is as follows and might apply to our shells so far as the 

 general characters go : 



"H testa imperforata, ovato-subulata tereti, pellucida, apertura- 

 oblonga" (Syst. Nat., ed. 12, p. 1249, 1767). Haldeman (Mon., p. 20) 

 refers fragilis to palustris. Moquin-Tandon (Hist. Moll., II, p. 471) 

 makes it a variety of stagnalis, and Louis Germain in a recent publi- 

 cation (Bull. Soc. Sci. Nat. L'Ouest France, ii, Tome III, p. 154) 

 raises it to the rank of a species, but says : "Test mince, fragile, corne 

 clair ou brun. Haut : 8-25 m. ; diam., 4-9 m." Locard and Westerlund 

 also consider it a small form. Moquin-Tandon (Moll. France, II, p. 

 471) makes appressa a synonym of stagnalis var. roseolabiata Wolf. 

 Kobelt (Mai. Blatt, XVIII, p. 108, 1871) thinks appressa is a synonym 

 of fragilis Linne, and includes bicolor Ziegler, roseolabiatus Wolf and 

 subula Pareyss. The figure of subula (fig. 9) given by Kobelt seems 

 almost identical with appressa. The raphidia of Bourg. (Spic. Mai., 

 pi. II, fig. II) resembles appressa, although Westerlund (Synopsis 

 Moll. Ext. Scan., p. 91) refers this and subula Pareyss to his subulata. 

 Var. elegans Leach also resembles the American shell. (See Martens, 

 Sitz.-Ber., Gess. Natur. Freunde, Berlin, 1899, p. 203.) Hazay (Mai. 

 Blatt., n. s. Ill, p. 162) makes appressa a species, with subulata West., 

 vulgaris West, and ampliata Clessin as varieties. His variegata (Mai. 

 Blatt., IV, pi. 2, fig. 7) looks not unlike jugularis Say as figured by 

 Haldeman. In view of the general confusion and uncertainty con- 

 cerning just what the Helix fragilis of Linne really is, it would seem 

 the best course to adopt for the American variety a name about which 

 there is no uncertainty. There are a number of forms found in Europe 

 w r hich closely resemble those of America, but as they are undoubtedly 

 cases of parallel development, they need not be considered in a study 

 of the American fauna. 



Some peculiar forms of stagnalis (pi. XXII, figs. 1-3) are figured 

 by Mr. Bryant Walker on plate 1, volume VI, of the Nautilus. They 

 are characterized by a rather short spire and a rather wide expansion 

 of lip. Some of these may be pathological examples (pi. XXII, fig. 3. 

 for example, which has the general aspect of var. sanctcemarice) , and 



