﻿514 MAKC, AUriAN A 



seems to be about north latitude 40°. It appears to be entirely 

 circumboreal, except that, so far as is known, it is missing in 

 the central part of the North American continent. Wetherby 

 has suggested that it may have been destroyed in this region 

 by the ice of the glacial epoch. But, see Walker, Pr. Mai. 

 Soc. London, IX, 1910, p. 126. It is found in the upper Mis- 

 souri and in Canada East, New York and the Nev\^ England 

 States. 



Mya margaritifera Lister, Hist. Anim. Ang. App., 1685, pi. 

 I, fig. I ; Hist. Conch., 1685, pi. cxux, fig. 4. — Linn^^jus, 

 Systema. Nat., 10th ed., I, 1758, p. 671.— Da Costa, Hist. 

 Nat. Brit., 1778, p. 225, pi. xv, fig. 33. — Knorr, Vergn., IV^ 

 1769, pi. XXV, fig. 2. — Pennant, Brit. Zool., IV, 1777, pi. 

 xuii, fig. 18. — Da Costa, Hist. Nat. Brit., 1778, p. 225, pL 

 XV, fig. 3.^Schroter, Fluss Conch., 1779, p. 168, pi. iv, fig. 

 I. — Donovan, Brit. Shells, III, 1801, pi. lxxiii. — Wood, 

 Gen. Conch., I, 1815, p. 107, pi. xxiii, figs. 1-3; Index Test., 

 1825, p. 12, pi. II, fig. 30. — Chenu, Bib. Conch., ist sen, I, 

 1845, P- 57' P^- XX, figs. I, 2. — Hanley (Wood), Ind. Test.,. 

 3d ed., 1856, p. 16, pi. II, fig. 30. 

 Mya margaritifera testa ovali oblonga. etc. — Chemnitz,. 



Conch. Cab., VI, 1782, p. 15, pi. \, fig. 5. 

 Baphicc margaritifera MeuschEn, Mus. Gevers, 1787, p. 472. 

 Unio margaritifera Draparnaud, Hist. Moll. Fr., 1806, p. 

 132, pi. X, figs. 17-19; pi. XI, fig. 5? — C. Peeiffer, Nat. 

 Deutsch. Land und Suss. Moll., 1821, Pt. i, p. 115, pi. v, fig. 

 II. 

 Margaritana margaritifera Schumacher, Essai. Nouv. Syst.,. 

 I, 1817, p. 124, pi. X, fig. 4. — Troschel, Arch, fiir Naturg., 

 XIII, pi. I, 1847, P- 270, pi. IV, fig. I. — Moquin-Tandon, 

 Hist. Moll. Fr., 1855, P- 623, pi. xxii, figs. 14-16. — Kuster, 

 Conch. Cab., 1856, p. 293, pi. xxxviii; xxxix, figs. 2-4. — 

 Chenu, Manual, 1859, II, p. 144, fig. 710. — Hartman and 

 Mtchener. Conch. Cest., 1874, p. 91. fig. 189. — Clessin, 

 Deutsch. Ex. Moll.. 1876, p. 440, fig. 293. — Simpson. Syn., 

 1000, p. 674. — Ortmann, Ann. Car. Mus.. ^7TI. 1012, p. 

 230, fig. I. 



