318 THE AMERICAN MIDLAND NATURALIST 
locally in the White, Black, and Neosho River basins. Simpson 
reports it for the Red River, Arkansas; Prof. Isely and Rev. 
Wheeler also report it for Arkansas.and Oklahoma. ‘Thus it seems 
to have supplanted fasciolarsis (=phaseolus) of the Tennessee 
drainage for the Southwest. 
Genus Obliquaria Rafinesque. 
1830—Obliquaria Rafinesque, Ann. Gen. Sci. Phys. Brux., p. 3or. 
1g00b, Simpson, p. 610. 
(Type Obliquaria reflexa Rafinesque.) 
ANIMAL CHARACTERS:—Branchial opening large with papillae; 
anal crenulated; supra-anal high with moderately short mantle 
connection to anal; inner laminae of inner gills free from the 
visceral mass except for a short distance anteriorly; palpi short 
and small; soft parts grayish; marsupium occupying only outer 
gills and consisting of 5-7 ovisacs placed posterior to the center 
of the gill and when gravid extending far beyond the edge of sterile 
marsupium; glochidia medium in size, semicircular, hinge-line 
with a slight up-curve in centre; conglutinates large, white, 
club-shaped, glochidia scattered all through the conglutinated 
mass. 
SHELL CHARACTERS:—Shel] medium in size, thick roundly 
trigonal, inflated; disk of one valve with row of large knob-like 
nodules running from beaks centrally ventrad and alternating 
with the knobs on the other valve; beaks sculptured with two 
or three concentric bars which, although heavy, are not well 
defined; epidermis greenish-yellow to brown with paintings of 
numerous interrupted rays; cardinals prominent and ragged; 
laterals short nearly straight; beak and branchial cavities not 
very deep; nacre white; female shell smaller and slightly inflated 
post-ventrad. 
MISCELLANEOUS REMARKS:—O. reflexa is the type and only 
member of this genus known thus far and is one of the most easily 
identifiable of all the Lampsilinae not only in its most unique 
marsupium, but also in the knobbed sculpture of its disk. The 
sex dimorphism of the shell for this type is rather peculiar as 
1836, pl. XXXVI, fig. 23) is the Pty. clintonense Simpson (1900-a and b) 
and hence this species, whose type locality is the Current River, Missouri, 
should be;:—Ellipsaria occidentalis (Conrad), 
