650 UNIO 
“This is a very small species and a single valve only, (the 
right), has been received by me. I do not think this is quite 
adult. The beak is not sufficiently perfect to observe any un- 
dulations. This shell is about the size of U. fabalis (nobis), 
and parzvus Barnes, but cannot be confounded with either of 
them. !t is a thinner shell than the former and less inflated 
than: the lattem: at(Lean. 
Only a single, broken valve, the right, is known. Lea de- 
scribes and figures it, but it is evidently a very young shell, 
too young to furnish reliable characters for identification. It 
may belong in the buck/eyi group, but of that I cannot be cer- 
tain. 
Unio BuxTontI B. H. Wright. ° 
Shell much elongated, decidedly rhomboid, inequilateral, 
convex; beaks low, scarcely inflated, their sculpture a few 
longitudinal corrugations; posterior ridge high, angled, lead- 
ing down to a point at the base of the shell; dorsal and basal 
lines parallel; dorsal slope obliquely truncated, the truncation 
meeting the dorsal line at an angle; anterior end cut away 
below, rounded, subangulate above; surface with delicate 
growth lines; epidermis tawny, covered with faint green rays, 
shining ; pseudocardinals compressed, two in each valve, the 
upper one of the right valve small; two straight laterals in the 
left valve and one in the right ; muscle scars well marked ; nacre 
rich copper-color, very bright. 
Length 50, height 19, diam. 11 mm. 
Type locality, Lakelets of Marion County, Florida. 
Unio buxtoni B. H. Wricnut, Naut., XI, 1897, p. 55.—S1mMp- 
son, Pr. Ac N. ‘Sci. Phila; 1900;-p.. 80, plh1, fe .65 Syl, 
TOO, p. 710. 
A rather remarkable form, the shell being much elongated 
and decidedly rhomboid. It is probably nearest to U. pinei, 
but is less inflated, more elongated in proportion and more 
decidedly rhomboid. It is probable that the specimen before 
me, whose measurements I have given, is young. 
‘ 
