﻿98 i.AiMi'Sir.is 



of Mass.. 1841, p. T09, fij?. 71. — BiNNGY, Gould's Inv.. 1870, 

 p. 169, f\^. 473. — De Kay, Zool. of N. Y., Pt. 5, 1843, P- '9^- 

 pi. XX, fig-. 239. — KusTER, Conch. Cab. Unio, 1861, p. 22^, 

 pi. Lxxv, fig. 4. — Reevr, Conch. Icon., XVI, 1865, P^- xxi, 

 fig. 94. — Hartman and Michener, Conch. Cest., 1874, p. 

 70, fig. 186. 

 Margarita (Unio) nasutus Lea, Syn., 1836, p. 37; 1858, p. 24. 

 Margaron (Unio) nasutus Lea, Syn.. 1852. p. 37 ; 1870. p. 60. 

 Lampsilis nasutifs Simpson. Syn., T900, p. 545. 

 Mya nasuta Katon, Zool. Text- Book. 1826, p. 218. — Wood, In- 

 dex Test. (Hanley), 1856, p. 199. pi. i, Supp., fig. 4. 

 Burynea nasuta Agassiz. Shells of New Eng., 185 1, p. 13. 

 Burynia (Burynia) nasuta Ortmann, Am. Car Mus., VIII, 



19 1 2, p. 343. 

 Unio rostrata Valenciennes, Rec. r)bs. Zool.. TI, 1833. p. 233, 



pi. i.iii, fig. 3. 

 Unio vaughanianus Sowerey, Conch. Icon.. X\'I. 1868, pi. 

 i.XT, fig. 308. 



No other living species seems to be very closely related to 

 this, though Unio Ushenanus is often mistaken for it. The lat- 

 ter is a smaller, more compressed, smoother species, and its 

 male and female shells are alike. There is a variety of Lamp- 

 silis snhrostrata found in the Wabash and in northern Ohio 

 that sometimes resembles nasuta, but the posterior beak is not 

 nearly so greatly drawn out. 



Group of Lampsilis subrostrata. 



Shell elliptical to elongate, distinctly pointed behind, the point 

 well above the middle of the height, that of the female conspic- 

 uously swollen at the posterior base and obliquely truncated 

 behind ; epidermis varying from olive to brown, generally more 

 or less rayed and slightly roughened ; beaks not prominent, 

 sculptured with fine, delicate, parallel bars, which are somewhat 

 looped in front and generally descend obliquely behind ; pscu- 

 docardinals usually compressed ; nacre bluish to purple. Ani- 

 mal with inner gills often more or less free from the abdom- 

 inal sac ; posterior base of mantle of female generally toothed. 



