SYNOPSIS OF THE NAIADES— SIMPSON. 621 



tANODONTA CYGNEA Linnaeus.i 



*Mytilus cygneus Linn.eus," Syst. Nat., 10th ed., 1758, I, p. 706, No. 1158. — 

 *MuLLER, Vermium, II, 1774, p. 208.— * Da Costa, Hist. Nat. Test. Brit., 

 1778, p. 214, pi. XV, fig. 2.— '^Gmelin, Syst. Nat., 13tli ed., 1778, p. 3335.— 

 *ScHKOTER, Flussconch., 1779,p. 162, pl.iii, fig. 1; ^ Eiu. Conch., Ill, 1783, 

 p. 440.— * Olivi, Zool. Adr., 1792, p. 125.— * Donovan, Brit. Shells, 11, 1800, 

 pi. LV. — Montagu, Test. Brit., 1803, p. 170.— Turton, Brit. Fauu., 1807, p. 

 165. — *Maton and Eackett, Tr. Linn. Soc. Lond., VIII, 1807, p. 109, pi. iii, 

 figs. 2, 3. — * Schumacher, Ess. Nouv. Syst., 1817, p. 106. — ""Dillwyn, Cat., 

 1817, p. 315.— Turton, Conch. Diet. 1819, p. 115.—* Sheppard, Tr. Linn. Soc. 

 Lond., XIII, 1820, p. 84, pi. v, fig. 3.—* Wood, Ind. Test., 1825, p. 58, pi. xn, 

 fig. 32/. — * Hanley, Ipsa Linn. Conch., 1855, p. 487. — * Wood, Ind. Test. Eev., 

 1856, p. 69, pi. xii, fig. 32/. 



*Anodontes cygneus Cuvier, Eegne An., II, 1817, p. 472. 



*Anodon cygneus Turton, Couch. Ins. Brit., 1822, p. 239. — * Fleming, Hist. Brit. 

 Moll., 1828, p. 415.— * Turton, Man. L. and F. W. Shells, 1831, p. 17, fig. 8.— 

 *" Brown, Land and F. W. Conch., 1836, p. 99, pi. xi, figs. l-3c. — * Thompson, 

 Ann. and Mag. N. Hist., VI, 1840, p. 196.—* Brown, 111. Eec. Conch., 1844, p. 79, 

 pi. xxviii, etc. — * Turton, Man. L. and F. W. Shells, 1857, p. 271, fig. 65, pi. i, 

 fig. 8.—* Tate, L. and F. W. Moll. Brit., 1866, pi. i.— *Sowerby, Conch. 

 Icon., XVII, 1870, pi. i, fig. 2. 



*Anodonta cygnea Draparnaud, Hist. Moll. Fr., 1806, p. 134, pi. xii, fig. 1 ; pi. xi, 

 fig. 6. — ^Millet, Moll. Maine et Loire, 1813, p. 76. — *Gaertner, A^ers. Syst., 

 1813, p. 38. — * Brard, Hist. Coq. Paris, 1815, p. 234, pis. ix, x.— * Klees, Desc. 

 Test., 1818, p. 43. — * Lamarck, An. sans Vert., VI, 1819, p. 84. — * C. Peeifeer, 

 L. and S. Moll., 1821, Pt. 1, p. Ill, pi. v, fig. 4.— Bosc, Hist. Nat. Coq., 1824, III, 

 p. 142. — *Blainville, Man., 1825, p. 358, pi. lxvi, fig. 1. — * Waardenberg, 

 Com. Hist. Nat. An., 1827, p. 37.—^ Stark, Nat. Hist., 1828, II, p. 89.— *Guerin, 

 Icon. Eegne An., II, 1829, pi. xxviii, fig. 5. — " Eossmassler, Icon., 1, 1835, p. 

 Ill, pi. Ill, fig. 67, etc.—" GouPiL, Hist. Moll. Sarthe, 1835, p. 81.— * WyatT, 

 Man. Conch., 1838, p. 68, pi. xi, fig. 2.— "PoRRO, Mai. Como., 1838, p. 110.— 

 *Gras, Moll. Isere, 1840. p. 70, pi. vi, fig. 7.— '^ Hanley, Test. Moll., 1842, p. 

 216; *Biv. Shells, 1843, p. 216.— * Scholz, Schleis. L. and AV. Moll., 1843, p. 

 118.— * MoRELET, Moll. Port., 1845, p. 100.— '^Puton, Moll. Vosges, 1847, 

 p. 68.— * Gasseiz, Moll. Ag., 1849, p. 189.— * Stein, Die Leb. Schneck., 1850, 



^The number of specific names bestowed on the Anodontas of Europe must runup 

 into the thousands. I have gone over the literature as carefully as possible, and 

 large series of specimens from many localities, and I confess that I am absolutely 

 unable to separate these forms specifically. The variations of form, size, color, 

 solidity, and even texture are sufficient for a large number of species if they were 

 not everywhere connected by intermediate examples. The new school of concholo- 

 gists has named every conceivable variation, and in very many cases distorted 

 individuals. Europe is a densely settled region, and it is possible that the waters 

 of the streams and ponds in many places may be so affected by sewage and other 

 off'al as to produce many changes in the mollusks living in them. I shall attempt 

 to recognize a few of the leading forms as varieties, referring them to the author 

 originally describing them, but on account of the enormous amount of literature 

 pertaining to these forms and its confused condition, I can not attempt to trace out 

 these varieties among the descriptions of subsequent writers. 



■^According to Hanley (Shells of Linna?tis, p. 144) the A. cygnea var cellensis of 

 Eossmassler (Icon., IV, 1830, pi. xix, fig. 280) is marked for this in the Linujean cab- 

 inet. It is a large, rather elongated shell, slightly biangulate behind, somewhat 

 cut away on the upper posterior part, and having fairly full beaks. 



