Bull. U, S. F. C, 1897. (To. face page 402.) 
Plate VII. 
LEFT VALVE OF UNIO RECTUS, OUTSIDE AND INSIDE VIEWS. 
The latter showed an extremely irregular mass of rich purplish nacreous matter, with many protuberances, lying between the hinge and the anterior 
adductor impression, and part y occupying the space of the latter. The shell is almost entirely white. The pearly pertuberan:es at the right of 
the hinge are of a rich putple color. The shell is pure white. 
