526 rnocKEniw.s OF THE NATIOXAL J/r>/;r.i/. VOL.XXH. 



Icon., XVI. ItH, pi. ii, fig. 7. *B H. WRIGHT, Check List, isxx. * P.F.TEL, 

 Couch. Sam., Ill, 1890, p. 147. 



Manjanta ( f'nio) avlatus LEA, Syn., 1836, p. 12; 1838, p. 14. 

 oit ( Unio) aclattis LEA, Syn., 1852, p. 20; 1870, p. 20. 



Tennessee River drainage; cited from Michigan by Sager and Miles, 

 certainly in error. They might have mistaken for this a rather high 

 specimen of<iblin. 



Genus LAMPSILIS Rafinesque, 182O. 

 (Type, Unio ovala* Say.) 



Lampsilis RAFIXKS^I-E, Ann. Gen. Sci. Phys. Brux., 1820, p. 298. 



Shell oval to elliptical, smooth or slightly concentrically sculptured, 

 usually without a posterior ridge; epidermis generally smooth and shin- 

 ing, often brilliantly rayed; beak sculpture, for the most part, consist- 

 ing of fine, parallel ridges, which show a tendency to fall into an ante- 

 rior and posterior loop; hinge with one or two pseudocardinals and 

 one lateral in the right valve, and two pseudocardinals and two lat- 

 erals in the left; female shell having a moderate and gradual inflation 

 in the post- ventral region opposite the marsupium. Animal with the 

 inner gills usually attached nearly or quite their entire length to the 

 abdominal sac; marsupium occupying the hinder part of the outer gills; 

 ovisacs distinct, separated by sulci, rounded below, having a fold near 

 their bases, the whole projecting below the inner gills; mantle edge 

 double and thickened, often swollen behind into a sort of flap in the 

 female. 



Section LAMPSILIS Rafinesque. 

 (Type, Unio oratus Say.) 



Shell inflated, rather thin, shining, sometimes having a posterior 

 ridge; beak sculpture coarse, consisting of a few, more or less, parallel 

 ridges, which scarcely fall into loops. Animal having the mantle of the 

 female usually toothed and thickened on the post basal portion, which 

 develops into a large, curious flap when the gills are filled with ova. 



t LAMPSILIS VENTRICOSUS Barnes. 



* Unio rentricosus BARNES, Am. Jl. Sci., VI, 1823, p. 267, pi. xin, fig. 14 (outline). 



* SAY, Am. Conch., No. IV, 1832, pi. xxxn. TERUSSAC, Guer. Mag., 1835, p. 

 2(5. *C. B. ADAMS, Thompson's History of Vermont, 1842, p. 167; F. W. 

 and L. S. of Vermont, 1842, p. 17.* HAXLEY, Test. Moll., 1842, p. 189; * Biv. 

 Shells, 1843, p. 189, pi. xxiv, fig. 8.* DE KAY, Zool. of N. Y., Pt. 6, 1843, p. 

 190. * CHKNU, Bib. Conch., 1st ser. Ill, 1845, p. 45, pi. xn, fig8. 1, 2. *H. 

 and A. ADAMS, Gen. Rec. Moll., II, 1857, pp.492, 495. * SOWERBY, Conch. Icon., 

 XVI, 1866, pi. XLIII, fig. 235.* B. H. WRIGHT, Check List, 1888. 

 M>ia ventricosus EATON, Zool. Text-Book, 1826, p. 221. 



* Mart/arita ( Unio) ventricosus LEA, Syn., 1836, p. 23; 1838, p. 18. 

 Margaron ( Unio) rentricosus LEA, Syn., 1852, p. 26; 1870, p. 41. 



* Lampsilis rentricosus BAKER, Moll. Chicago, Pt. 1, 1898, p. 94, pi. xn, figs. 3-5. 



" SMITH, Bull. U. S. Fish Com., 1899, p. 291, pi. LXXXIII. 



