NAIADES OF MISSOURI 



Q. nodulata (Raf.) — (i. b) 



Q. fragosa (Contrad) — (i. b) 

 Q. aspera (Lea) — (i. c) 

 Q. nobilis (Conrad) — (2. a) 

 Q. verrucosa (Raf.) — (i. c) 

 Q. metanevra (Raf.) — (i. c) 

 (7). Q. metanevra Wardii (Lea) — (i. b) 



19. Q. cylindrica (Say) — (3. c) 

 b. — Only outer gills marsupial. 



(a) — Supra-anal opening absent; beak sculpture zigzag; disk greatly 

 sculptured Genus VL RoTundaria (Raf.) 



20. R. tuberculala (Raf.)^(i. c) 



21. R. graniferaihca.) — (i. b) 



(b) — Supra-anal presjent but short; beak sculpture concentric but 

 disappearing toward disk which is mostly unsculptured. 



Genus VIL PlEThobasus (Simpson; 



22. P. Cooperianus (Lea)— (2. c) 



23. P. aesopus (Green) — (i. b) 

 Genus VIII. Pleurobema (Raf.) 



24. P. obliquum (Lamarck) — (i. b) 



(8). P. obliquum plenum (Lea) — ^(3. c) 

 (9). P. obliquum pyramidatum (Lea) — (i. c) 

 (10). P. obliquum catillus (Conrad) — (i. c) 

 (11). P. obliquum coccineum (Conrad) — (i. c) 



25. P. catillus (Conrad) — (3. c) 



26. P. coccineum (Conrad) — (3. c) 



27. P. missourense (Marsh) — (3. c) 



28. P. Utterbackii Frierson — (3. c) 

 Genus IX. Euliptio (Raf.) 



29. E. nigra (Raf.) — (2. c) 



30. E. dilalala (Raf.) — (2. a) 



(12). E. dilatala subgibbosa (Lea) — (3.0) 

 (13). E. dilatata delicata (Simpson) — (3. c) 

 Genus X. Uniomerus (Conrad) 



31. U. tetralasma (Say) — (i. a) / 

 (14). U. tetralasma comptodon (Say) — (i. a) 



(B). — Mantle connection between anal and supra-anal openings always 

 present, very long and moderate; inner laminae of inner gills usually 

 free from the visceral mass; marsupia occupying entire outer gills 

 only, distended ventrad and with lateral water-tubes when gravid; 

 post ventral margin of mantle not differentiated; glochidia subtrian- 

 gular, or spadiform, spined; bradytictic or long period ("Winter") 



breeder Sub-Family II. Anodontinae Ortmann 



a. — Inner la'minae of inner gills free from visceral mass; beak sculpture 

 coarse, double-looped. 



(a) — Mantle connection between anal and supra-anal openings 

 moderately long; hinge rather complete, shell sculptured and 

 somewhat thick Genus XI. Symphynota (Lea) 



