LYMNZIDZ OF NORTH AMERICA. oLT 
Lymnea desidiosa Morse, Amer. Nat., III, p. 651, 1870 (part) —BAKER, 
Nautilus, XXII, p. 20, pl. III, figs. 1-2, 1908. 
SHELL: Of medium size, solid, ovate to elongated in form; peri- 
ostracum pale. horn colored, darker in some specimens; surface dull, 
lines of growth crowded, conspicuous, crossed by fine impressed spiral 
lines ; the body whorl is frequently malleated ; whorls five to six, regu- 
larly and rapidly increasing in size, well rounded, the body whorl quite 
convex; spire acutely conic or elongated, as long as or a little longer 
than the aperture ; sutures well impressed, rather deeply in some speci- 
mens; nuclear whorls 14 in number, brownish horn in color, and in 
outline like those of palustris; aperture ovate or roundly ovate, rounded 
below and slightly angled above; outer lip with an internal varix ; 
inner lip narrow, triangular, reflected over the umbilical region, leaving 
a small chink; the callus on the parietal wall is heavy and sometimes 
causes the aperture to be continuous; there is a columellar plait and 
the axis is slightly twisted. 
Length. Breadth. Aperture length. Breadth. 
15.00 7.50 8.00 3.00 mill. Say’s autotype 
14.25 7.50 elds) 3350), aS ¥ a 
15.00 8.00 8.00 ALTO Williamsville, N. Y. 
14.00 8.00 8.00 3.50 “ 3 = 
17.00 8.00 7.50 ACOON ses Seneca Lake, N. Y. 
15.50 7.50 6.50 3150) * a 
Types: Autotypes, Acad. Nat. Sct., Philadelphia, two specimens, 
No. 58731. 
Tyre Locatity: Cayuga Lake, N. Y. 
AnimaAL: Not examined alive, but alcoholic specimens appear 
externally like palustris. 
Jaw: As in palustris. 
Raputa (Pl. VIII, fig. I.): Formula PetststHHetee 
(34-1-34) ; the teeth are in all essential respects like those of palustris ; 
the marginals of desidiosa begin more abruptly than is the case with 
palustris. 
GeniratiA: Not differing from those of palustris; one specimen 
gave the following measurements: 
Penis- Prost. Penis Penis-sac 
Penis. sac. Vas.def. duct. ret. ret. Shell. Locality. 
150 2.75 1000 350 225 200 1400 New York. 
Rance: New York to Indiana. <A species of the humid division 
of the Transition and Upper Austral life zones, and of the Canadian 
and the Upper Mississippian regions. The specimens examined have 
all been from the Carolinian division of the Upper Austral of western 
New York. The Indiana record is that of Say on page 211 of his 
