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Lymneus pingxjis.— Shell oval, rather ventricose, pale, dirty 
yellowish ; whorls nearly four, rapidly diminishing to the apex, 
which is dull fulvous ; suture moderate ; spire rather more than 
half the length of the aperture; aperture large; labrum with the 
inner margin a little thickened. 
Total length eleven-twentieths of. an inch; aperture rather more 
than seven-twentieths ; breadth seven- twentieths. ^ 
Proportionally shorter and much more dilated than other species 
of the country, with the exception of L. macrostomus, nob., from 
which it is readily distinguished. It inhabits the Delaware and 
Schuylkill rivers near Philadelphia, in company with L. catmco- 
pium, nob. 
Lymneus galbanus.— Shell subovate; whorls nearly five, 
very convex ; suture very deeply impressed ; apex acute ; body 
whorl a little flattened in the middle ; aperture not dilated ; colu- 
mella with the sinus of the fold very obvious. 
Length three-tenths of an inch : aperture rather more than half 
. the whole length. 
For this shell I am indebted to Mr. Nuttall, who obtained it in 
a marl pit near Franklin, New Jersey. He considers it fossil, as 
well as numerous specimens of Planorhis campanulatus, Valvata 
tricarinata, and Phyaa lieterostropha, found with it. I have never 
seen a recent specimen, but the present corresponds with some in- 
dividuals belonging to the Philadelphia Museum, also said to be 
fossil. 
Physa ancillabia.— Shell heterostroj)he, subglobose, pale yel- 
lowish ; whorls rather more than four, very rapidly attenuated ; 
spire truncated, hardly elevated beyond the general curve of the 
surface ; suture not impressed ; aperture but little shorter than 
the shell, dilated ; labrum a little thickened on the inner margin. 
Length more than one-half of an inch. 
The spire of this species is unusually short, truncated at tip 
like the Paludina decisay nob. ; and the suture is so inconspicu- 
ous as to give rise to the name which I have chosen for it. My 
brother, B. Say, obtained it in the Delaware river near Easton, 
and Mr. Jessup collected numerous specimens in the Connecticut 
river, above Hartford. It may be distinguished from P. Jietero- 
stropha^ nob., by the shorter and truncated spire, inconspicuous 
