LYMNID2 OF NORTH AMERICA. 403 
Specimens in the Lea collection (Smith. No. 118655) are similar 
to specimens in the Philadelphia Academy (No. 58703) which were 
received from Mighels, and which correspond with his figures and de- 
scriptions, and it is these forms which must be taken as correctly 
representing Mighels’ species. Specimens in the collection of Mr. 
Bryant Walker, which were received from Mighels, are figured on 
plate XLII, figures 23-25. The material examined is very uniform and 
the species appear to be very distinct. An examination of the axis 
shows that decollata is a member of the catascopium group of the 
subgenus Stagnicola, and was not correctly placed in Radix by Binney, 
Dall, Tryon and other conchologists. The peculiar swelling out of 
the periphery of the body whorl in decollata will at once distinguish it 
from all related forms. The writer has not seen specimens from Con- 
necticut or from different parts of Canada, and the records of Lins- 
ley, Bell and others in which decollata is cited from these localities is 
greatly to be questioned. They will probably be found to be forms 
of catascopium or oronensis. 
Galba sumassi (Baird). Plate XLI, figures 11-17. 
Limnea sumassi Baird, Proc. Zool. Soc., p. 68, 1863—Cpr., Rep. Brit. 
Assoc., p. 673, 1864.—BinneEy, L. & F.-W. Sh. N. A., II, p. 43, fig. 56, 1865.— 
Tryon, Amer. Journ. Conch., III, p. 196, 1867—Cpr., Smith. Mis. Coll., p. 155, 
1872.—Sows., Conch. Icon., XVIII, Limn., sp. 34, 1872——SrTearns, Proc. Nat. 
Mus., XIV, p. 101, 1891; XXIV, p. 291, 1901—WuiutTEAvEs, Ottawa Nat., XX, 
p. 115, 1906. 
Limnophysa sumassi Tryon, Amer. Journ. -Conch., I, p. 251, 1865—CAaLtt, 
Bull. U. S. Geol. Surv., II, p. 371, 1884 (part). 
Lymnea sumassi Lorp, Nat. in Brit. Col., II, p. 363, 1866. 
Limneus sumassi Ciessin, Kiister, Conch. Cab., p. 387, taf. 53, fig. 4, 1886 
(figure poor). 
Limnea nuttalliana var. sumassi Cooper, Proc. Cal. Acad. Sci., IV, p. 96, 
1870 (part). 
Lymnea catascopium var. sumassi Dati, Alaska Moll., p. 78, 1905 (part). 
SHELL: Narrow, elongated, attenuated, fusiform in some speci- 
mens, varying from thin to rather solid; periostracum light, whitish 
horn, with two or three rest period bands; surface shining, lines of 
growth coarse and heavy, wrinkled and crowded about the aperture, 
crossed by very heavy impressed spiral lines; nuclear whorls rounded, 
smooth, dark brown color, in size about as in catascopium; whorls six, 
flatly rounded, slowly enlarging; last whorl somewhat flat-sided nor- 
mally; spire rather long, pointed, a trifle longer than the aperture; 
sutures well impressed ; aperture elongate-ovate, somewhat semi-lunate, 
a little effuse anteriorly ; peristome thin, acute, bordered within by a 
narrow black band which marks a rest-varix; parietal wall with a 
