QUADRULA 847 
Margarita (Unio) apiculatus Lea, Syn., 1836, p. 15): 1838, <p: 
iit 
Margaron (Unio) apiculatus Lea, Syn., 1852, p. 22; 1870, p. 
33- 
Quadrula apiculata Simpson, Syn., 1900, p. 778. 
Unio nobilis Conrap (part), Jl. Ac. N. Sci. Phila., 1854, p. 
267, Pls SORVin, Noy 2. 
Close to aspera, but, as a rule, not quite as elongated. It 
is more densely covered with pustules, which are often ar- 
ranged in partly zigzag patterns, they are finer, and are equally 
numerous in the radial depression in front of the posterior 
ridge. Those on the posterior and median ridges are not en- 
larged and the epidermis in mature specimens is more ashy- 
colored and less brown than in aspera. 
QUADRULA RUMPHIANA (Lea). 
Shell subquadrate, subinflated, solid, equilateral or having 
the beaks slightly nearer to the posterior end; beaks high, 
moderately full; their sculpture consisting of sharply doubly 
looped bars; posterior ridge full, rounded or showing a slight 
inclination towards being biangulate, ending at the posterior 
base of the shell, and having in front of and behind it a de- 
cided radial depression ; anterior end round; base line incurved 
in front of the posterior ridge; posterior end almost squarely 
truncated, sinused above the posterior ridge; surface more or 
less covered with low tubercles of various sizes, the posterior 
ridge nearly or quite smooth; post-dorsal slope with radial, 
nodulous plications; epidermis greenish in the young shell, 
rich reddish-brown in the adult shell, shining; pseudocardinals 
subtriangular, rough, but not much split; laterals short, 
straight, that of the right valve more or less double; beak 
cavities deep; muscle scars well marked; nacre silvery, thinner 
and iridescent behind. 
Length 90, height 78, diam. 45 mm. 
Type locality, Western Georgia. Also Alabama in the Gulf 
drainage. the 
