760 PROCEEDINGS OF THE NATIONAL MUSEUM. 



tPLEUROBEMA RECLUSA B. H. Wright. 



* Unio reclusus B. H. WRIGHT, Naut., XI, 1898, p. 3. 



* Pleurobema reclusa SIMPSON, Pr. Ac. N. Sci. Phila., 1900, p. 82, pi. i, fig. 2. 



Ocklockuee River, Leon County, Florida. 



(Group of Pleurobema brnmbyana.) 



Shell' oval, inflated, moderately solid, faintly swollen at post basal 

 region; beaks rather prominent, somewhat distant from the anterior 

 end; beak sculpture not seen; disks irregularly, concentrically sculp- 

 tured; epidermis dark olive to blackish, striate; pseudocardinals sub- 

 radiate, slightly compressed; beak cavities shallow; nacre iridescent 

 posteriorly, somewhat thickened in front. 



tPLEUROBEMA BRUMBYANA Lea. 



* Unio briimleyanus LEA,' Proc. Am. Phil. Soc., II, 1841, p. 82. 



* Unio briiml>y<uni8 LEA, Tr. Am. Phil. Soc., VIII, 1842, p. 245, pi. xxvi, fig. 62; 



* Obs., Ill, 1842, p. 83, pi. xxvi, fig. 62.* CONRAD, Pr. Ac. N. Sci. Phila., 

 VI, 1853, p. 245.* H. and A. ADAMS, Gen. Rec. Moll., II, 1857, p. 492.* B. 

 H. WRIGHT, Check List, 1888. * P.ETEL, Conch. Sam., Ill, 1890, p. 146. 



* Margaron ( Unio) brumbyanus LEA, Syn., 1852, p. 31 ; 1870, p. 49. 



t * Unio conco/orLEA.Pr. Ac. N. Sci. Phila., V, 1861, p. 40; * Jl. Ac.N. Sci. Phila., 

 V, 1862, p. 89, pi. xii, fig. 237; *Obs., VIII, 1862, p. 93, pi. xn, fig. 237. 



* SOWERBY, Conch. Icon , XVI, 1868, pi. LXXXIII, fig. 440.* B. H. WRIGHT, 

 Check List, 1888. * P^TEL, Conch. Sam., Ill, 1870, p. 148. 



* Margaron ( Unio) concolor LEA, Syn., 1870, p. 49. 



Alabama River system. 



(Group of Pleurobema argentea.) 



Shell solid, oval to rhomboid, generally compressed, beaks high but 

 not inflated, well removed from the anterior end, with strong, irregular 

 sculpture, which is curved up and swollen behind where the bars are 

 slightly looped ; epidermis brownish to straw color, sometimes having 

 a few broken, blotched rays; teeth strong; cicatrices deep and distinct. 

 Animal unknown. 2 



tPLEUROBEMA SIMULANS Lea. 



*Unio simulans LEA, Pr. Acad. N. Sci. Phila., I, 1871, p. 190; *J1. Acad. N. Sci. 

 Phila., VIII, 1874, p. 18, pi. v, fig. 15 ; * Obs., XIII, 1874, p. 22, pi. v, fig. 15. 



* B. H. WRIGHT, Check List, 1888. 



Black Warrior and Cahawba rivers, Alabama; Pine Barren Creek, 

 Escambia County, Florida. 



'So written in Proceedings; no doubt a typographical error, as the species was 

 named after Brumby. 



2 The species placed here are puzzling and seem to stand between Unio and 

 Pleurobema. The color and the beak sculpture incline me to place them with the 

 latter, and some of the species seem to show relationship with such forms as P. 

 pudica and bigbyana. 



