NO. 1 205. S TNOPSIS OF THE NA I A DES SIMPSON. -637 



(Group of Anodonta woodiana.) 1 



Shell oval, inflated, sometimes narrowed in front, pointed behind, 

 and often a little produced at the posterior base, slightly winged in the 

 post-dorsal region ; beaks full, sculptured with numerous strong con- 

 centric ridges, which are either straight in the center of the disk or 

 slightly doubly looped. There is often a faint posterior ridge, which 

 may be double, making the shell feebly biangulate behind; dorsal 

 scars one or two under the beaks; muscle scars irregular. 



Animal with the gills large, equal in size, rounded below, free the 

 greater part of their length from the abdominal sac, somewhat 

 wrinkled ; marsupium occupying the entire outer gills, forming thick 

 brown pads when filled ; palpi large, subelliptical, free from the mantle 

 a long way; mantle having a wide, thickened edge; branchial opening 

 crowded with dark papillae; anal opening with no papillae, but having 

 purple ridges inside; superanal opening closed nearly its whole length. 2 



t ANODONTA WOODIANA Lea. 







* Symphynota ivoodiana LEA, Tr. Am. Phil. Soc., V, 1834, p. 42, pi. v, fig. 13; * Obs., 



I, 1834, p. 154, pi. v, fig. 13. 



* Margarita (Anodonta) woodiana LKA, Syn., 1836, p. 48; 1838, p. 29. 

 *Anodon woodiana CATLOW and REEVE, Conch. Nom., 1845, p. 68. *SOWERBY, 



Conch. Icon., XVII, 1870, pi. xxxvi, fig. 149. 

 * Anodonta woodiana HANLEY, Test. Moll., 1842, p. 215 ; * Biv. Shells, 1843, p. 215. 



*H. and A. ADAMS, Gen. Rec. Moll., II, 1857, p. 503. *CLESSIN, Conch. 



Cab. Ano., 1875, p. 146, pi. XLVIII, figs. 1, 2. 



*Margaron (Anodonta) u-oodiana LEA, Syn., 1852, p. 47; 1870, p. 75. 

 ^Symphynota magnifica LEA, S Tr. Am. Phil. Soc., V, 1834, p. 42, pi. v, fig. 14 ; Obs., 



I, 1834, p. 155, pi. v, fig 14. 



* Margarita (Anodonta) magnifica LEA, Syn., 1836, p. 48; 1838, p. 29. 

 * Anodonta magnifica HANLEY, Test. Moll., 1842, p. 215; Biv. Shells, 1843, p. 215. 



* H. and A. ADAMS, Gen. Rec. Moll, II, 1857, p. 503.* CHENU, Man., 1859, II, p. 



146, fig. 719. * SCHRENCK, Reis and F. Am. Lande., II, 1867, p. 718, pi. xxvm, 



figs. 1, 2.* PJETEL, Conch. Sam., Ill, 1890, p. 181. 

 *Anodon magnifica CATLOW and REEVE, Conch. Nom., 1845, p. 67. SOWERBY, 



Conch. Icon., XVII, 1870, pi. xxv, fig. 96. 



*Margaron (Anodonta) magnifica LEA, Syn., 1852, p. 47; 1870, p. 75. 

 *? Anodonta aurata KUSTER, Conch. Cab. AUG., 1853, p. 30, pi. vi, fig. 2. 



1 Fischer has made a subgenus Pteranodon (Man. Conch., p. 1003) for A. magnifica, 

 but I do not see any need of giving it and the related species any higher rank 

 than that of a group. The shell and animal differ but little from those of other 

 Anodontas. 



2 A group closely agreeing in general characters, but having enormous individual 

 variation. Pere Heude has bestowed specific names on a great number of forms, 

 most of which are, I think, merely mutations of Lea's woodiana. Fortunately the 

 U. S. National Museum possesses in the Morelet collection a large series of author's 

 specimens, and the excellent figures in the Conchyliologie Fluviatile Nanking 

 enable me to straighten out this difficult group to some extent. 



3 Larger and rather more finely developed than A. woodiana, but the large series 

 of material I have examined absolutely connects the two. 



