DES MOINES ACADEMY OF SCIENCE. 25 



I Tnio compressissimiig, Lea. 



(Trans. Am. Phil. Soc., :M S rics, Vol. X. Pi. VI II. Fi-. 23.) 

 Holston river. Tennessee. Is this more than a variety of Unio 



j Unio eonasaugensis, Lea. 



(Observations on the Genus Unio, Vol. XIII, Pi. X, FL, r . 30.) 



Coiiasauga creek, in east Tennessee, and Swamp creek, Whitfield county, 

 (Georgia. Very close to U. argenteus Lea. 



f Unio con radian us. Lea. 



(Trans. Am. Phil. Soc., Vol. V, PI. IX, Fig. 23.) 



Southeastern Virginia; Asheville, North Carolina; Powell's and Holston 

 rivers, Tennessee. This species belongs to the group of which U. acutissimus 

 is the type. U. pcnicillatus and U. rubellinus also group with this species. 



The species was described and figured as U. conradicus. 



*Unio cuoperianus, Lea. 



(Trans. Am. Phil. Soc., Vol. V, PI. VIII, Fig. 21.) 



Ohio river, near Cincinnati, to Mississippi river, near Muscatine, Iowa; south 

 to the Holston and Tennessee rivers. This species belongs to the group typified 

 by U. piistnlosiis, Lea. 



fUiiio copei, Lea. 



(Jour. Acad. Nat. Sci., Phila., 2nd Series, Vol. VI, PI. XLVII, Fi-. 120.) 

 "Holston river, Smyth county, Virginia," is the only locality reported. The 

 species is very close to U. pybasli, grouping with it and 77. obscurus. 



fUnio cor, Conrad. 



(New Fresh Water Shells of the United States, PI. Ill, Fig-. 3.) 

 Elk and Flint rivers, Tennessee. 



*Unio cornutus, Barnes. 



i \m. Jour. <>r S:-i and Arts, 1st Series. Vol. VI, PI. IV, Fig., 5a, 5b.) 



Ohio to Etowali rivers, Georgia; Coosa river, Alabama, at Wetumpka; Ala- 

 bama river, atSelma; to Trinity river, Texas; north to Kansas, Iowa, and Min- 

 nesota. This species constantly maintains its own well known characters 

 throughout its wide distribution. There is no other form closely resembling it. 



CATALOGUE 17. 



