U N I 0. 



Species 9. (Fig. 9, and 12, Mus. Cuming.) 

 Unio tubeuculatus. Uii. testa orbicidari, compressiiis- 

 cidd, posiice Jlexitoso-lrwncatd, medio et latere postico 

 de umbonibus ad margines rude irregulariter verru- 

 cosis ; epidermide fuho-oUvaced. 

 The tubekcled Unio. Shell orbicular, rather com- 

 pressed, posteriorly flexuously truncated, middle and 

 posterior side irregularly rudely warted from the 

 umlioes to the margins; epidermis fulvous-olive. 

 llAFiNEsauE, Mon. Coq. de la riv. Ohio, Ann. Gen. Sc. 

 Phys. Brux. 1820, vol. 5. p. 287. 

 Unio verrticusus, Barnes. 

 Unio titiercidosus, Valenciennes. 

 Hnb. North America. 



The wart tubercles in this species are peculiarly rudely 

 developed, and the compressed flexuous truncation of the 

 posterior side of the shell is also a specific character. 



Species 10. (Mus. Cuming.) 



Unio turgidus. U/i. testa siibqiiadrato-roi/indald, pos- 

 tici-flexuosd, decUvi-truiicatd, medio subcontractd, medio 

 et circa nmbones concentrice Hoduso-luberculutd ; epi- 

 dermide nigricante-oUvacen. 



The swollen Unio. Shell somewhat squarely rotun- 

 date, posteriorly tlexuous, and slopingly truncated, 



ratlicr contracted in the middle, concentrically no- 



dosely tnbercled in the middle and around the um- 



boes ; epidermis blackish-olive. 

 Lea, Trans. Amer. Phil. Soc. 1834, vol. (>. pi. .5. f. 11. 



Obs. vol. 2. p. 11. 



Uiiio Mortoni, Conrad. 

 Hah. New Orleans, North America. 



Rather flexuously contracted on the posterior side, the 

 sculpture beitig in the form of concentrically inclined no- 



Species 11. (Mus. Cuming.) 

 Unio apiculatus. Uh. testa subquadrul.o-ocatd, pMi id 

 Jtexuoso-aiigulatd, deinde declivi-truncatd, medio con- 

 cavo-coiitractd, undigue nitide rugoso-nodulatd ,■ cpi- 

 derw ide fidvo-olivaced. 

 Thk bee-covered Unio. Shell somewhat squarely 

 ovate, posteriorly flexuously angled, then slopingly 

 truncated, concavely contracted in the middle, neatly 

 rugosely noduied throughout; epidermis fulvous- 

 olive. 

 Say, Amer. Couch, pi. 52. 

 llab. North America. 



ricsembling the preceding species in form, but uiore 

 ([uadrately flexuous, and beautifully sculptured tliroughout. 



