NO. 1205. SYNOPSIS OF THE NAIADES— SIMPSON. 807 



Adams, Geu.Rec. Moll., ir, 1857, p. 497.— *Chenu, Man., 1859, II, p. 142, fig. 

 700.— * Reeve, Coucli. Icon., XVI, 1865, pi, xxv, fig. 191.— *Heude, Conch. 

 Fluv. Nank., II, 1877, pi. xvi, fig. 36.— '^ P.aETEL, Couch. Sam., Ill, 1890, p. 154. 

 "" Margarita ( Unio) grayanus Lea, Syn., 1838, p. 14. 



* Margaron ( Unio) grayanus Lea, Syn., 1852, p. 21 ; 1870, p. 32. 



* Unio grayii Griffith, Grif. Cuv., XII, 1834, pi. xxi, fig. 3. • 



China. 



tNODULARIA GLADIOLUS Heude. 



* Unio gladiolus Heude, C. Fluv. Nank., II, 1877, pi. xvi, fig. 35.— ^P^tel, Conch. 



Sam., Ill, 1890, p. 154. 



China. 



tNODULARIA TRIFORMIS Heude. 



^ Unio triformis Heude, Conch. F. Nank., II, 1877, pi. xvi, fig. 34. 

 -" Unio distoritis Heude, Conch. F. Nank., VIII, 1883, pi. lxii, figs. 122, 1226.— 

 *P.ETEL, C. Sam., Ill, 1890, p. 151. 



China. 



tNODULARIA OXYRHYNCHUS von Martens. 



* Unio oxyrhynchus von Martens, Mai. Blatt, VII, 1861, p. 57.— ' Kobelt, Abh, 



Senck. Nat. Ges., XL, 1879, p. 420, pi. xiii, figs. 3, 4.—* Pfeiffer, Nov. Conch., 

 V, 1879, p. 192, pi. CLVii, figs. 4, 6.—* P.etel, C. Sam., Ill, 1890, p. 162.— MON 

 Ihering, Abh. Senck. N. Ges., XVIII, 1893, p. 156. 



Japan. 



Section CYLINDRICA Sirapson, 1900. 

 (Type, Nodularia eylindrica Simpson.) 



Shell inflated, solid, cylindrical, smooth, with a rounded posterior 

 ridge; teeth heavy, pseudocardinals radiate, curved. 



NODULARIA CYLINDRICA Simpson. 



* Unio grayanus Schrexck,- Reis. unci Forsch. im Am. Lande, 1867, p. 694, pi. xxvii, 



figs. 1-3. 

 Nodularia eylindrica Simpson, Pr. Ac. N. Sci. Phila., 1900, p. 84. 



Amur land. 



Section NODULARIA Conriid, 1853. 

 (Type, Unio douglasiw Gray.) 



Characters the same as the genus. 



(Group of Nodularia douglasice.) 



Shell olive to blackish, subsolid; surface generally more or less cov- 

 ered with nodules arranged in subradiating or chevron-shaped jjatterns. 



' I have seen a curious shell in the collection of Mr. Bryant Walker shaped some- 

 thing like the N. grayana, but quite heavy and decidedly inflated in the post-basal 

 region. It may be an old graya,na, but is so eroded that I can not be certain. 



-Schrenck supposes this to be the Unio grayanus of Lea, but it is very diiferent. 

 It is a large, heavy, cylindrical shell, apparently without sculpture, and the figure 

 does not show plainly whether it has any posterior ridge. A large form between 

 grayanus and oxyrhynchus is found in Korea, according to von Martens, Sitzber. Nat. 

 Fr., 1885, p. 77. 



