864 FROCEEDINGS OF TRE NATIONAL MUSEUM. 



*t Casialia hanleyana Sowerby, Conch. Icon., XVII, 1869, pi. i, fig. 5.— <P.etel, 



Conch. Sam., Ill, 1890, p. 189. 

 "^ Casialia caroUnensis Sowerby, Conch. Icon., XVII, 1869, pi. ii, fig. 6. — 



^PiTEL, Conch, gam., Ill, 1890, p. 189. 

 " Casialia cordata Strobel, Mat. Mai., Ft. I, 1874, p. 75. 



Amazon and Eio de la Plata Eiver systems. 



I TETRAPLODON QUADRILATERUM d'Orbigny. 



* Casialia quadrilaiera ij'Orbigny, Guer. Mag., Xo. 62, 1835, p. 42. — ** Hanley, 



Test. Moll., 1842, p. 173; *Biv. Shells, 1843, p. 173.— ''d'Orbigky, Voy. Am. 

 Mer , 1843, p. 599, pi. lxxiii.— *Troschel, Arch, fur X^at., XIII, 1847, Pt. 1, 

 p. 222.—* VON Ihering, Arch, filr Nat., 1893, p. 89. 



* Mya amhigua Wood, lud. Test. Eev., 1856, p. 200, j)l. i (supp. ), fig. 9. 



* Casialia acuiicostaKvPE., Moll. Xouv., Ill, 1857, p. 77, pi. xiv, fig. 3.— *Sowerby, 



Conch. Icon., XVII, 1869, pi. in, figs. 12, 12a, 12fc.— "P.etel, Conch. Sam., 

 Ill, 1890, p. 189. 



* Casialia cordata H. and A. Adams, Gen. Eec. Moll., II, 1857, p. 509, ])l. cxx; III, 



figs. 2, 2a. — *SowERBY, Conch. Icon,, XVII, 1869, pi. ii, fig. 8. — *P.etel, 

 Conch. Sam., Ill, 1890, p. 189. 



* Casialia latiquadraia Sowerby, Conch. Icon., XVII, 1869, pi. ii, fig. 10. — *PyETEL, 



Conch. Sam., Ill, 1890, p. 189. 



Tropical Soatli America east of the Andes. Perhaps a form of am- 

 bigims. 



tTETRAPLODON OVATUS Sowerby. 



* Casialia ovaia Sowerby, Couch. Icon., XVII, 1869, pi. i, fig. 4. — "P^tel, Conch 



Sam., Ill, 1890, p. 189. 



Brazil. 



tTETRAPLODON RETUSUS Hupe. 



* Casialia amhigua Sowerby, Conch. Man., 1839, fig. 140. 



* Casialia reiusa Hupe, Moll. Nouv., Ill, 1857, p. 75, pi. xiv, fig. 2. — *Sowerby, 



Conch. Icon., XVII, 1869, pi. i, fig. 2.—* P.etel, Conch. Sam., Ill, 1890, p. 189. 



Gniana. 



TETRAPLODON QUADRATUS Sowerby. 



X 



* Casialia quadrata Sowerby, Conch. Icon., XVII, 1867, pi. ii, figs. 7, 7a, lb.— 



" Pjetel, Conch. Sam., Ill, 1890, p. 189. 



TETRAPLODON SCHOMBERGIANUS Sowerby. 



"* Casialia schombergiana Sowerby, Conch. Icon., XVII, 1869, pi. xiv, fig. 3. — 

 * Pjltel, Conch. Sam., Ill, 1890, p. 189. 



Guiana. 



(Group of Tetraplodon multisulcatus.) 



Shell small, somewhat compressed, with a moderate posterior ridge,, 

 and covered throughout with delicate ridges j teeth more Uniouoid than 

 in the typical Tetraplodons. 



Animal uuknowu. 



