AN.O DON. 
Puate XXI. 
‘Species 82. (Mus. Sowerby.) 
Anopon Harperuensis. An. testd@ elongato-ovatd, 
tumidd, obliquad, extus levigatd, viridi, obscuré 
flavido-radiatd ; margine dorsali utrinque recto, 
ad terminos cuneato ; umbonibus tumidis, ovatis, 
prominentibus, ad apices biseriatim tuberculatis ; 
latere postico oblique producto; margine laterali 
declivi, termino acuminato ; latere antico brevius- 
culo ; margine ventrali omnino convexo ; margine | 
cardinali crasso. 
Tne Harretn River Anopon. Shell elongate-ovate, 
tumid, oblique, smooth without, green, obscurely 
rayed with yellow; dorsal margin straight on both 
sides, cuneate at the ends; umboes tumid, ovate, 
prominent, tuberculated at the apex in a double 
row; posterior side obliquely produced, lateral 
margin sloped, end acuminated; anterior side 
rather short; ventral margin convex in every part ; 
hinge margin thick. 
Species 83. (Mus. Sowerby.) 
ANopON DECORA, An. testd magnd, solidd, ovato- 
acuminata, levigatd, olivaceo-viridi, ad latera 
leviter concentricé undulata ; intis alba iridescenti, 
margine cardinali incrassato; umbonibus pro- 
minentibus, ovatis, ad apices acute biseriatim tuber- 
culatis ; latere postico producto, obscuré biangulato, 
acuminato ; latere antico breviusculo ; margine 
dorsali arcuato, cuneato ; margine ventrali omnind 
convexo. 
THE pecorous Anopon. Shell large, solid, ovate-acu- 
minate, smooth, olive-green, obscurely rayed, 
lightly concentrically undulated at the sides; 
within iridescent white, with cardinal margin 
thickened; umboes prominent, ovate, sharply 
tuberculated in two rows at the apices; posterior 
side produced, obscurely biangular, acuminated; 
anterior side rather short; dorsal margin arched, 
cuneate; ventral margin convex in every part. 

Lea. Obs. on Unio, III., p. 62, pl. 19, f. 42. Lea. Obs. on Unio. 
Hab. Harpeth River. Hab. 2 
The nacre is in some specimens very slightly salmon- The shell here figured is the nearest representative 
tinted. we can find of Lea’s species, and appears to agree with 

it pretty accurately. 
August, 1869. 
