392 THE AMERICAN MIDLAND NATURALIST 
tical, inflated; disk smooth; beaks high and full; post dorsal 
ridge somewhat alated; post umbonal ridge biangulated; epidermis 
glossy black. 
INTERNAL STRUCTURES:—Cardinals double in both valve; 
laterals prominent, blade-like; umbonal and branchial cavities 
deep and rounded out; nacre rich purple. 
Sex Length Height Diameter Locality 
Gi 20, Xa 75> xe simi White R., Hollister) 
( 
9125 X 70 *X\> 44mm (Ss AP aR ors thn 
oie Be ok BO xs (ViCunim Gna ” Hollister) 
9 70 X 47 X 34mm CR exsist" n : ) 
MISCELLANEOUS REMARKS:—The young shells of P. purpurata 
are thin and fragile but later become thick and solid; resembling 
alata in form and nacre but is more so alated not compressed. 
This shell only appears in the White and Neosho River basins 
and is one of the few not found in the Mississippi. Its favorite 
habitat is deep water and mud bottoms. It is hoped its glochidium 
may be verified and more proportionate measurements given 
than Lea was able to record. 
Proptera laevissima (Lea). 
(“Paper Shell,’’ “‘Double Wing.’’) 
Pl. IX, Figs. 19 and 20; Pl. XXVI, Figs. 94 A—D. 
1830—Symphynota laevissima Lea, Tr. Am Phil Soc., III, p. 444, 
DI x hice 2'3'. 
t900b—Lampsilis laevissima Simpson, Pr. U. S. Nat. Mus., XXII, 
Pp. 574. 
1912b—Proptera laevissima (Lea) Ortmann, An. Car. Mus., VIII, 
Pp. 334. 
ANIMAL CHARACTERS 
NUTRITIVE STRUCTURES:—Branchial and anal openings very 
tubular, directed away from each other; anal smooth; supra-anal 
high, well separated from anal by mantle connection; inner 
laminae of inner gills entirely connected to visceral mass; palpi 
broader than long, connected about one-half of the length antero- 
dorsad; color of soft parts a modest tan, except for mantle edges 
at siphonal openings and the area over nephridium. 
REPRODUCTIVE STRUCTURES:—Marsupium large, kidney- 
shaped occupying over half of posterior part of outer gills and 
consisting 50-60 narrow ovisacs somewhat distended transversely 
