Call — The Unionidce of Arkansas. 65 



LIST OF PLATES. 



Plate I. Unio clavus Lamarck. 



II. Unio crassidens Lamarck. 



III. Unio luteolus Lamarck. 



IV. Uuio obliquus Lamarck. 



V. Uuio purpuratus Lamarck. Male and female 

 VI. Unio purpuratus Lamarck. Female. 

 VII. Unio rectus Lamaick. 

 VIII. Unio retusus Lamarck. 

 IX. Unio rotundatus Lamarck. 

 X. Unio metanevrus Raflnesque. 

 XI. Unio cylindricus Say. 

 XII. Unio schoolcraftii Lea. 



XIII. Uuio schoolcraftii Lea. Varieties. 



XIV. Unio schoolcraftii Lea. Figures 1-4. 

 Unio pustulosus Lea. Figures 5-6. 



XV. Unio dorfeuillianus Lea. Figures 1-2. 

 Unio refulgens Lea. Figures 3-4. 

 XVI. Margaritana complanata Barnes. 

 XVII. Uuio breviculus Call. From U. S. Nat. Museum. 

 XVIII. Unio ozarkensis Call. From U. S. Nat. Museum 

 XIX. Unio sayii Ward. Figures 1-2. 



Unio sayanus Conrad. Figures 3-5. 

 XX. Unio excultus Conrad. Figures 1-3. 

 Unio tetralasmus Say. Figures 4-5. 

 XXI. Unio ligamentinus Lamarck. 



