& 
FRESH WATER AND LAND SHELLS. 279 
trossulus has some resemblance to the amygdalum, herein described, being nearly of the 
same size. ‘The latter, however, is a thinner shell, is not oblique, and the rays are dis- 
tinct over the whole disk. 
Unio occuttus, Pu. 41. Fic. 7. 
Testa ellipticd, compress, inequilaterali, postice subbiangulatd; valvulis tenuibus; natibus subprominentibus undulatisque; 
epidermide nitidd, tenebroso-fuscd, obsolete radiatd; dentibus cardinalibus subgrandibus; lateralibus longis subcurvisque; mar- 
garuld purpured et iridescente. 
Shell elliptical, compressed, inequilateral, subbiangular behind; valves thin; beaks somewhat prominent and 
undulated ; epidermis polished, dark-brown, and obscurely radiated ; cardinal teeth rather large; lateral teeth long 
and somewhat curved; nacre purple and iridescent. 
Hab. Black Creek and Lake Monroe, Florida. S. B. Buckley. 
My cabinet and cabinets of Dr. Budd and Mr. Buckley. 
Diam. .8, Length 1.2, Breadth. 2.1 inches. 
Shell elliptical, compressed, inequilateral, subbiangular behind; umbonial slope slightly 
angular; substance of the shell thin; beaks somewhat prominent and minutely undulated 
at the tip; ligament long and thin; epidermis smooth and polished, dark-brown, with 
obscure rays over the whole disk; cardinal teeth rather large, and disposed to be double 
in both valves; lateral teeth long, rather thin, and somewhat curved; anterior cicatrices 
distinct; posterior cicatrices confluent; dorsal cicatrices under the plate posterior to the 
cardinal tooth; cavity of the shell shallow; cavity of the beaks small and subangular ; 
nacre purple and iridescent. ‘ 
Remarks.—The three specimens before me vary but little in size or form, and are all 
purple—others may differ in colour. It is rather a diminutive species, allied to compla- 
natus, but may easily be distinguished from that shell. The epidermis being filled with 
dark-green rays over the whole disk, gives it a very dark hue. In the more perfect 
individuals, the exterior is very smooth and highly polished. 
Unto Monroensis, Pr. 41. Fic. 8. 
Testa ellipticd, subcompressd, inequilaterali, posticé subangulatd; valvulis crassis; natibus prominulis; epidermide rufo- 
fused; dentibus cardinalibus parvulis; lateralibus longis, lamellatis curvisque; margaritd lividd et iridescente. 
Shell elliptical, rather compressed, inequilateral, somewhat angular behind; yalves thick; beaks somewhat promi- 
nent; epidermis reddish-brown ; cardinal teeth rather small ; lateral teeth long, lamellar, and curved ; nacre livid and 
iridescent. : 
Hab. Lake Monroe, Florida. S. B. Buckley. 
My cabinet and cabinets of Dr. Budd and Mr. Buckley. 
Diam. 1.1, Length 1.7, Breadth 2.8 inches, 
Shell elliptical, rather compressed, inequilateral, somewhat angular behind; umbonial 
slope angular; substance of the shell thick, thinner behind; beaks somewhat prominent ; 
ligament rather long and thick; epidermis smooth, dark-reddish brown, nearly black on 
the posterior slope; cardinal teeth rather small, disposed to be double in both valves; 
lateral teeth long, lamellar, and curved; anterior cicatrices distinct; posterior cicatrices 
distinct; dorsal cicatrices placed under the anterior end of the lamellar tooth; cavity of 
ay shell rather shallow; cavity of the beaks rather deep and angular; nacre livid and 
iridescent. 
VOL. IX.——74. 
