74 RAFINESQUE’S 
ribbed with a double epidermis, the outer rufous, the inner green- 
ish: inside bluish purple.—Length 7-12, diameter 1-3, axis 1-4 of 
breadth. 
er Salt river, rare, small, 14 inch; cardinal tooth almost as in 
. Leptodea, lamellar tooth well curved, and flexuose. 
85 Sp. Unio diaphanus, (Metaptera? diaphana 1821.) Shell 
very thin, transparent, oval-elliptic, swelled, broader behind, with a 
small wing, surface smooth horny, inside, pale incarnate. Length 
3-4, diameter and axis 3-8 of the breadth. Var. lineolata with ful- 
vous greenish lines. 
In small streams of Kentucky, one or two inches, rare, cardinal 
tooth compressed, crenulate, lamellar well curved. 
86 Sp. Unio lasmabrachys (Metaptera? do. 1820.) Shell 
rather thick, oval triangular, swelled, truncate behind with an arched 
ridge, surface rugose horny, inside bluish white, small truncate wing, 
beaks prominent. Length 5-7, diameter 3-7, axis 2-7 of the 
breadth. 
Licking river, &c., 3 or 4 inches, rare, deep cavity inside: teeth 
wide apart, cardinal crenulate, lamellar very short, broad and trun- 
cate in the right valve. This and the last belong more to Metaptera 
by the teeth than the wings. 
87 Sp. Unio rimosus, (Hurynia rimosa. 1823.) Shell elliptic, 
thick, thinner, broader, and rimose behind: surface olivaceous nearly 
smooth, inside bluish white. Length 2-3, diameter 1-6, axis 1-4 of 
length. : 
In the Cumberland river, rare, small 14 inch. Resembling some 
Amblemas, but evidently transversal, cardinal tooth crenulate, lam- 
ellar smooth, short, nearly horizontal, but a little curved towards the 
back. Perhaps a peculiar 8. G. near to Lpioblasma, it might be 
called Lemiow. 
88. Sp. Unio fulvus. (Hurynia fulva.—t 823.) Shell elliptical, 
thick before, sloping behind, surface depressed nearly smooth, bright 
fulvous or rufous outside and inside. Length one half, diameter and 
axis-one fifth of the breadth. 
Var. 2. Fuscata, brownish rufous outside, pale inside. 
Var. 2. Rufa, quite rufous outside, iridescent inside. 
In Green river, Rockcastle river, &c.,—rare, fine shell, 2 or 3 
inches, cardinal tooth crenate, lamellar long and straight. Near to 
my U,. auratus. 
