II06 PARRKYSIA 



ish with green, concentric bands, sometimes it is almost a uni- 

 form green ; on the posterior slope there are generally two or 

 three dark rays and there are rarely faint rays on the disk. 

 Left valve with two ragged pseudocardinals and two laterals ; 

 right valve with two pseudocardinals and one lateral ; there 

 are usually a few tubercles behind the pseudocardinals ; beak 

 cavities rather deep ; anterior scars impressed ; nacre white, 

 sometimes salmon-tinted in the cavity, iridescent behind ; pal- 

 lial line often with a trace of a posterior sinus. 

 Length 42, height 30, diam. 18 mm. 

 Length 43, height 30, diam. 21 mm. 

 Length 52, height 35, diam. 22 mm. 

 India. 

 Mya comigata Miiu-ER, Verm. Terr, et Fluv., 1774, Pt. 2, p.. 

 214; Besch. Ges. Nat. Ber. IV, 1779, p. 56, pi. iii^, figs. 7, 8. 

 — ScHROTKR, Fluss, Conch., 1779, p. 181, pi. IX, fig. 3. — 

 Wood, Gen. Conch., L 1815, p. 108, pi. xxiv, figs. 1-3. — 

 Mawk, Linn. Conch., 1823, pi. iv, fig. 3. — Wood, Ind. Test., 

 1825. p. 12, pi. II, fig. 31a; 1856, rev. ed., p. 16, pi. 11, fig. 31. 

 Unio corrngata Lamarck, An. sans Vert., VL 1819, p. 78. — 

 DeshayivS, Enc. Meth., 11, 1827, p. 584, pi. ccxlviii, fig. 8.. 

 Unio (Potamida) corrngata Swainson, Tr. on Mai., 1840, p. 



268, fig. 51 ; p. 281, fig. 57. 

 Unio corrugatus Retzius, Diss. Hist. Nat., 1778, p. 18. — Kus- 

 TER, Conch. Cab. Unio, 1862, p. 289, pi. xcvii, figs. 3, 4. — 

 Sow^ERBY, Conch. Icon., XVI. t868, pi. lxxt, fig. 360. — Han- 

 ley and Theobald, Conch. Ind., 1876, p. 21, pi. xlv. figs. 



2-5- 

 Margarita (Unio) corrugatus Lea, Syn., 1836. p. 29; 1838,. 



p. 21. 

 Margaron (Unio) corrugatus Lea, Syn., 1852, p. 20: 1870, p.. 



30- 

 Parreysia corrngata Simpson, Syn., 1900. p. 841. 

 Mya spuria Gmelin, Syst. Nat.. T3th ed., 1788, p. 3222. 

 Mya gaditana Schreibers, Versuch., 1703, p. 

 Unio multidentatus Philippt, Conch. Ill, 1847, P- 4^. pi- tii, 



fig. 4.— KusTER, Conch. Cab. Unio.. 1856, p. 136, pi. xxxvi,. 



Margaron (Unio) multidentatus Lea, Syn., 1870, p. 50. 



