44 DESCRIPTION OF NEW 
Hab. Para, South America, Mr. C. M. Wheatley. 
My cabinet and cabinet of Mr. Wheatley. 
Diam. .8, Length 1.1, Breadth 2.2 inches. 
Shell smooth, transverse, rather inflated, gibbous, very inequilateral, angular behind, 
irregularly rounded before, slightly compressed near to the anterior margin and straight 
on the dorsal line; substance of the shell thick; beaks swollen, a little elevated and placed 
near to the anterior margin; ligament very long and very thin, scarcely protruding above 
the dorsal line; epidermis cinnamon-red, reddish-brown along the margin, totally without 
rays, the lines of growth approximate; posterior slope very long, rather wide, somewhat 
compressed, with a thin, coloured, elevated hair-like line passing from the beaks to the 
posterior margin; umbonial slope elevated and rounded; anterior cicatrices distinct, the 
smaller one very minute; posterior cicatrices confluent; no visible dorsal cicatrices; pal- 
leal cicatrices slightly impressed; cavity of shell rather shallow; cavity of the beaks rather 
shallow and subangular; nacre with minute strie from the beaks towards the margin, 
of a beautiful light salmon colour, and magnificently iridescent. 
Remarks.—Of this beautiful South American Anodonta, I have but a single specimen 
before me. It differs from any of the species described by Spix or D’Orbigny, and is 
altogether a very remarkable species. It is a stout shell, with a nacre which is softer, 
richer and more satin-like than in any I have ever seen. The nacre is a light salmon 
colour, with a tint of purple, which gives the most surprising softness and brilliancy to it. 
The margin is darks but the nacre immediately in contact with it gives a line of fine blue 
and green. The triangular fosset at the end of the ligament, common to the South 
American species, is very marked in this. 
I owe this and many other fine shells of this family to my friend Mr. Wheatley, and 1 
dedicate this beautiful one to him. 
Anoponta SwHaerrertana. PI. XXVI. Fig. 50. 
Testa levi, oblonga, inflata, inequilaterali, postice angulata; valvulis subcrassis ; natibus prominentibus, 
ad apices undulatis ; epidermide castaned, nitidd, obsoleté radiata; margarita salmonis colore tinctd. 
Shell smooth, oblong, inflated, inequilateral, angular behind; valves rather thick; beaks somewhat prominent, 
undulated at the beaks; epidermis shining, chestnut-coloured and obsoletely rayed; nacre salmon coloured. 
Hab. Horn Lake Creek, Tenn., Mr. Shaeffer. 
My cabinet and cabinet of Mr. Shaeffer. 
Diam. 1.2, Length 1.7, Breadth 2.8 inches. 
Shell smooth, oblong, inflated, inequilateral, angular behind, rounded before; dorsal 
line under the beak, interrupted by a double, tuberculous callus; substance of the shell 
thick; beaks somewhat prominent, submedial, coarsely undulated at the tip; ligament 
rather short and thick; epidermis shining, chestnut coloured, obsoletely rayed, with dis- 
tinct distant marks of growth; posterior slope broad and somewhat flattened; umbonial 
slope angular from beak to margin; anterior cicatrices confluent; posterior cicatrices con- 
fluent; dorsal cicatrices placed above the cavity of the beaks and partly on the tuberculate 
swellings; palleal cicatrix slightly impressed; cavity of the shell deep and broad; cavity 
of the beaks deep and subangular; nacre salmon-coloured and brilliant. 
