678 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxii. 



^ Margaron ( Unio) crassim Lea, Syn., 1852, p. 39; 1870, p. 62.' 



* U7iio anricularhis Spenglek, Skriv. Nat. Selsk., Ill, 1792, p. 54.— *Westek- 



LUND, Faim. Pal., II, Pt. 7, 1890, p. 50. 

 Unio ragosa Poiret, Coq. Flnv.,et Terr, de I'Aisne, 1801, p. 105.- 



* Unio sinuala Lamarck, Au. sans Vert., VI, 1819, p. 70.-^ — Blainvii.le, Man., 



1825, p. 639, pi. Lxvii, fig. 3. — "' Desiiayes, Enc. M6th., II, 1827, p. 151, pi. 

 ccxLViir, fig. 1; II, 1830, p. 579, pi. ccxlviii, fig. 1, la, Ih. * — ' Sganzin, Mem. 

 Hist. Nat. Strasb., Ill, 1842, II, p. 8.-— "Puton. Moll.Vosges, 1847, p. 72. 



*Unio (Poiamida) sinuata Swainson, Tr. on Mai., 1840, p. 268. 



*Unio simtatits Rossmassleij, Icon., Ill, 1836, p. 22, pi. xiii, fig. 195. — * Gassies, 

 Moll, de I'Ag., 1849, p. 198.—* Dupuy, Hist. Moll. Fr., 1852, p. 630, pi. xxiii, 

 fig. 7. — * RossMASSLER, IcoD., Ill, 1854, p. 38, pi. lxx, fig. 853, 853a.'' — 

 *Moquin-Tandox, Moll. Terr, and Fluv. Fr., II, 1855, p. 567; III, pi. xlviii, 

 figs. 1-3.— 'Drouet, Nay. Fr., II, 1857, p. 61, pi. ii.— ■ Hessling, Die Perl, 

 and Hire Perlen, 1859, p. 184. — "Sowerby, Conch. Icon., XVI, pi. lxii, 

 fig. 31L— *P/ETEL, Couch. Sam, III, 1890, p. 167.— * Locard, Coq. de Fr., 

 1893, p. 151, fig. 164. 



*fUnio litomUsC. Pfeiffer, Nat. Deutsch. L. nnd S. W. Moll., Pt. 1, 1821, p. 117, 

 pi. V, fig. 12.7 



*Unio crassissimus Hanley, Test. Moll., 1842, p. 209; ^Biv. Shells, 1843, p. 209, 

 pi. XXIII, fig. 54. — '■ Catlow and Reeve, Conch. Nom., 1845, p. .58. 



* Unio gargottw Philippi, Moll. Sic, 1836, p. 66. — ^'Rossmassler, Icon., VII and 



VIII, 1838, p. 26, pi. XXXV, fig. 493.8—" Drouet, Jl. de Conch., XXIX,, 1881, 

 p. 25.—* Westerlund, Fann. Pal., II, Pt. 7, 1890, p. 156. 



Southern Europe; possibly into Asia Minor and southwest Siberia. 



tMARGARITANA LAOSENSIS Lea. 



* Unio laosensis Lea, Pr. Ac. Nat. Sci. Phila., VII, 1863, p. 190; *J1. Ac. N. Sci. 



Phila., VI, 1866, p. 63, pi. xxi, fig. 61 ; - Obs., XI, 1867, p 67, pi. xxi, fig. 61.— 

 *SowERBY, Conch. Icon., XVI, 1866, pi. xlvii, fig. 256.— * P.etel, Conch. 

 Sam., Ill, 1890, p. 156. 



* Margaron ( Unio) laosensis Lea, Syn., 1870, p. 62. 

 Unio svla Theobald (where?). 



Laos Mountains, Cambodia; Siam. 



' It has often been impossible to determine what species has been referred to by 

 authors under the name crassvs. In cases where they have cited this sjiecies from 

 the north of Europe I have no doubt that they either had Margarilana margaritifera 

 or Unio hatuviis before them. In those cases where I could not be certain as to what 

 was meant I have omitted references. 



^According to Moquiu Tandon this is U. sinuaUis Lamarck. 



3 Lamarck refers to Encyc. Meth., 1797, pi. ccxlviii, figs, la, lb, which seem to be 

 the crassus of Retzius. Lea, who examined Lamarck's type, says he had thought it 

 was the Margaritaiia margaritifera, but that it had lateral teeth. (Obs. I, pp. 35, 198.) 



^ These figures look something like a heavy inflated Lampsilis alatns Say, but are 

 probably the crassus of Retzius. 



■''Given to Sganziu by M. Fabert, chief of batalliou of infantry, as having been 

 found at St. Paul in the Isle of Bourbon, but Sganziu very nuich doubts the locality. 

 Of course it was never found in the Indian Ocean region. 



''A magnificent figure of this fine species, and in a, which shows the hinge, the 

 laterals are plainly deliueated. 



"Dr. Lea is doubtful about this being litoralis, and I am sure it is not. It appears 

 more like M. crassus than anything else. 



«Dr. Lea makes this a synonym of Pfeifier's elongatuliis, which is, I believe, quite 

 near to U. pictoriim. Rossmassler's figure shows a shell very much like Margaritana 

 margaritifera, but it has lateral teeth. 



