l.AMELLIDF.NS 1167 



fUnio testudinarius SpENGLER, Skriv. Selsk. Nat., Ill, 1793, 65. 

 fUnio tnmcattts Spkngler, Skriv. Selsk. Nat., Til, 1793, p. 65. 

 Unto marginalis Lamarck, An. sans Vert., VI, 1819, p. 79. — 



Dkshayes, Enc. Meth. II, 1827, p. 151, pi. ccxevii, fig. i. — 



Haneky, Biv. Shells, 1843, P- 206, pi. xx, fig. 53. — Kuster,. 



Conch. Cab. Unio, 1861. p. 239, pi. lxxx, fig. 4. — Sowerby, 



Conch. Icon., XVT, 1867, pi. i.ix, fig. 297. — Hanley and 



Theobald, Conch. Ind., 1876, p. 20, pi. xuii, fig. 2. 

 Margarita (Unio) marginalis. Lea, Syn., 1836, p. 37; 1838, 



p. 24. 

 Margaron (Unio) marginalis Lea, Syn., 1852, p. 38; 1870, 



p. 60. 

 Lamellidcns marginalis Simpson, Syn., 1900, p. 854. 

 Unio anodontina Lamarck. An. sans Vert., VT, 1819, p. 80. 

 Unio anodontinns KusTER, Conch. Cab. Unio, 1861, p. 240, pi. 



Lxxx, fig. 15. 

 Symphynota bilineata Lea, Tr. Am. Phil. Soc, I\^, 1831, p. 98, 



pi. XI, fig. 19; Obs., 1. 1834, p. 108, pi. XI, fig. 19. 

 Margarita (Unio) bilineatiis Lea, Syn., 1836, p. 38; 1838, p. 25. 

 Unio bilineatus HaneEy, Biv. Shells, 1843, p. 207, pi. xxi, fig. 



30. — Sowerby, Conch. Icon., XVI, 1868, pi. lxxi, fig. 365. 

 Margaron (Unio) bilineatus Lea, Syn.. 1852, p. 38 ; 1870, p. 61. 

 fUnio evanesccns Mousson, Moll. Java, 1849, P- 9^^- pl- xvii,. 



fig. 2. 

 Unio doUchorhynchus Tapperone Canefri, Am. ]\Ius. Civ. 



Gen., 1889, p. 348. 

 Unio gianelli Tapperoxe Caxeeri, Am. Mus. Civ. Gen., 1889, 



P- 353- 



I use Lamarck's name for tliis species because the U. test- 

 udinarius and truncatus were only briefly and imperfectly 

 described, and never figured, their habitats being given as 

 Greenland. Lamarck refers to the figures in Enc. Meth., pi. 

 2^7, figs. I, Iff, jb, ic, which very accurately represent the shell 

 we know as Unio marginalis. 



An exceedingly variable species and I have only attempted 

 to give a description of fairly typical forms as understood by 

 Hanley and Theobald and Lea. The form is usually nearly 



