NO. 1205. SYNOPSIS OF THE NAIADES— SIMPSOK. 585 



*Cristaria spatiosa voN Ihering, Abh. Senck. Nat. Ges., XVIII, 1893, p. 145. 



-Barhala spatiosa P.etel, Conch. Sam., Ill, 1890, p. 175. 



*Dipsas plicata var. japonica Kobett, Abh. Senck. Nat. Ges., XI, 1879, p. 429, pi. 



XLVII. 



Japan. 



Subgenus PLETHOLOPHUS Simpson, 1900. 

 (Type, Symplnj)iota discoidea Lea.) 



Shell short-elliptical, lenticular, scarcely thickened in front, with 

 compressed beaks which are sculptured with low, wide, concentric 

 ridges, scarcely winged in front or behind, pointed posteriorly; epider- 

 mis smooth, somewhat rayed; hinge teeth v^ery feeble, often nearly 

 wanting; dorsal scars few ; muscle scars faint. Animal unknown. 



tCRISTARIA DISCOIDEA Lea. 



* Symphynota discoidea Lea, Tr. Am. PhiL Soc, V, 1834, p. 75, pi. xi, fig. 33 ; " Obs., 



1, 1834, p. 187, pL XI, fig. 33. 

 'Barhala discoidea H. and A. Adams, Gen. Rec. Moll., II, 1857, p. 501.. — * Chenu, 



Man., 1859, II, p. 145, fig. 716.—^ PyETEL, Conch. Sam., 1890, p. 175. 

 *Dipsas discoidea Kuster, Conch. Cab. Unio, 1862, p. 306, pi. c, fig. 1. 



* Margarita ( Unio) discoideus Lea, Syn., 1836, p. 47; 1838, p. 28. 



""Unio discoideus Hanley, Test. Moll., 1842, p. 214; "* Biv. Shells, 1843, p. 214, pi. 



XXI, fig. 57. — " Catlow and Reeve, Conch. Nom., 1845, p. 58. 

 ^Margaron {Unio) discoideus Lea, Syn., 1862, p. 46; 1870, j). 74. 



* Unio tenuis Gray, GrilHth's Cuv., XII, 1834, p. 601 (index), pi. xxiv, fig. 2.' 

 * Anodonta chinensis Kuster, Conch. Cab. Ano., 1853, p. 51, pi. xii, fig. 3. 

 ''UniomagnificHs Sowerby, Conch. Icon., XVI, 1867, pi. LVii, fig. 289. 



' Anodonta gnineriana Clessin, Conch. Cab. Ano., 1875, p. 172, pi. lvi, figs. 3, 4. 



China. 



CRISTARIA PARVULA Heude.- 



* Dipsas parvulus Heude (part). Conch. Fluv. Nank., IV, 1878, pi. xxxil, fig. 65. 

 ' Barbala parvula Pjetf.i^, Conch. Sam., Ill, 1890, p. 175. 



China. 



CRISTARIA REINIANA von Martens. 



*Cristaria reiniana voN Martkns, .Jahrb. Mai. Ges., II, 1875, p. 136, pi. iii, fig. 4. 



* ^ Dipsas reiniana Kobelt, Abh. Senck. Nat. Ges., XI, 1879, p. 432, pi. xii, fig. 4; 



XXI, fig. 2. 

 ^Anodonta reiniana voN Ihering, Abh. Senck. Nat. Ges., XVIII, 1893, p. 147.'' 

 *Barhata reiniana Pjetel, Conch. Sam., Ill, 1890, p. 175. • 



Japan. 



'A brief description is given in the index only. Gray"s and Lea's names seem to 

 have been published the same year, and I do not know which apjieared first. I use 

 Lea's because it is the one generally known. 



-I am doubtful whether this is more than a variety of C. discoidea. Heude's figure 

 on plate liii is a very different thing, which I have called C. radiata. 



"' Martens says it has distinct cardinals and laterals. 



