NO. 1205. sYXorsrs OF THE NAIADES SIMPSON. 889 



tDIPLODON DORSUOSUS Go. Id. 



* I'nio dorsuosus GOULD, Pr. Bost. Soc. N. H., Ill, 1850, p. 296; * U. S. Expl. Exp., 



XII, 1852, p. 430, figs. 540, 540o, 540ft; * Otia Conch., 1862, p. 89.* H. and A. 

 ADAMs.Gen. Rec. Moll., II, 1857, p. 497. *P.ETEL,Conch. Sam., Ill, 1890,p. 151. 

 *Margaron (Unio) dorsitosus LEA, Syn., 1852, p. 21. 



I'nio napeanensis CONRAD, Pr. Ac. N. Sci. Phila., V, 1852, p. 10; *J1. Ac. N. Sci. 

 Pbila., 1854, p. 296, pi. xxvi, fig. 4. *H. and A. ADAMS, Geu. 1 ec. Moll., II, 

 1857, p. 498. * REEVE, Couch. Icon., XVI, 1865, pi. xxni, fig. 2. * P^ETEL, 

 Conch. Sam, HI, 1890, p. 160. 



* Margaron ( Unio) napeanensis LEA, Syn., 1852, p. 20; 1870, p. 30. 



Nepeaii River, Australia. 



DIPLODON GLENELGENSIS Dennant. 



* Unio glenelf/ensis DEXNANT, Pr. Roy. Soc. Viet., X, 1898, p. 112, pi. iv. 

 Glenelg River, Victoria. 



(Group of Dlplodon menziezi.) 



Shell subrhomboid ; beak sculpture not strong, consisting of broken, 

 nodulous ridges curving toward each other below, with generally a 

 smooth space between, not extending over the shell. 



Animal as in the subgenus. 



tDIPLODON MENZIEZI Gray. 



* Unio menziezi GRAY, In Dieffenbach's N. Z., II, 1843, p. 257. * ?MUSGRAVE, Phot. 



Conch., 1863, pi. ir, fig. 1. * BUTTON, N. Z. Moll., 1880, p. 160. * P.KTEL, 

 Conch. Sam., 1890, p. 159. 



* Unio menziezianus REEVE, Couch. Icon., XVI, 1865, pi. xxix, fig. 152. 



* Margaron ( Unio) menzieni LEA, Syn., 1870, p. 46. 



* Unio aucklandica GRAY, In Dieffenbach's N. Z., II, 1843, p. 257. * HUTTON, N. Z. 



Moll., 1880, p. 161. 



*fUnio aucklandicus SOWKRBY, Conch. Icon., XVI, 1866, pi. xxx, fig. 156. 

 *P,ETEL, Conch. Sam., Ill, 1890, p. 145. 



* Margaron (I'nio) aucklandiciia LEA, Syn. ,1870, p. 45. 



tDIPLODON MENZIEZI var. RUGATUS Hutton. 1 



* Unio rugatus HUTTON, Tr. N. Z. Inst., XVI, 1884, p. 216. *P^CTEL, Conch. Sam., 



Ill, 1890, p. 166. 



tDIPLODON MENZIEZI var. HOCHSTELLERI Krauss. 



*Unlo hoclistellm DUNKER, Mai. Bl., VIII, 1862, p. 153. *SOWERBY, Couch. Icou., 

 XVI, 1868, pi. LXXXVI, fig. 463. *HUTTON, N. Z. Moll., 1880, p. 161. *P^: 

 Conch. Sam., Ill, 1890, p. 155. 2 



'The name rugatim was applied previously to a European Unio by Rossmassler; 

 but it m:iy be used as a varietal name. This seems to be a small form of menziezi 

 which sometimes merges into hochstelleri. 



2 Suter believes this to be only a pathologic form of menziezi. He says iu a letter 

 to the author that he has seen the same kind of disease among small rugatus. 



