LYMNAIDA 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 Linné. After 
an examination of European and American specimens, | 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 Linné 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., Il, 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, corné 
clair ou brun. Haut: 8-25 m.; diam., 4-9 m.’’ Locard and Westerlund 
also consider it a small form. Moquin-Tandon (Moll. France, I, p. 
471) makes appressa a synonym of stagnalis var. roseolabiata Wolf. 
Kobelt (Mal. Blatt., XVIII, p. 108, 1871) thinks appressa is a synonym 
of fragilis Linné, 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. Mal., 
pl. I, fig. IL) resembles appressa, although Westerlund (Synopsis 
Moll. Ext. Scan., p. 91) refers this and suwbula Pareyss to his subulata. 
Var. elegans Leach also resembles the American shell. (See Martens, 
Sitz.-Ber., Gess. Natur. Freunde, Berlin, 1899, p. 203.) Hazay (Mal. 
Blatt., n. s. III, p. 162) makes appressa a species, with subulata West., 
vulgaris West. and ampliata Clessin as varieties. His variegata (Mal. 
Blatt., IV, pl. 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 Linné 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 
which 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 (pl. 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 (pl. XXII, fig. 3, 
for example, which has the general aspect of var. sanctemarie), ané 
