U N I 0. 



Species 25. (Mus. Cuming) 



Unio metanevek. I'll, testa subquadrato-orblculari, 

 gibbosiuscula, postice Jlexuoso-angulatd, delude com- 

 presse truncatd, undique irregulariter nodoso-tubercu- 

 latd et verrucosa ; fulvo-otivaced, viridi variegata. 



The settler Unio. Shell somewhat squarely-orbi- 

 cular, rather gibbous, posteriorly flesuously augled, 

 then compressly truncated, irregularly nodosely tu- 

 bercled and warted throughout ; fulvous-olive, varie- 

 gated with green. 



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

 Phys. Brux. IS-'O, vol. v. p. 287. 

 Unio nodosHs, Barnes. 

 Unio rugosHS, Barnes. 

 Telederma metanevra, Swain son. 



Hab. North America. 



There is a characteristic irregularity about the sculpture 

 of this species. 



Species 26. (Fig. a, b, Mus. Cuming.) 

 Unio prasinus. Un. testa ovatd, regidariter convexd, 

 postice. obtuse aiigidari, delude cornpresse truncatd, 

 lavigatd, in medio et versus angulum obtuse verrucosa, 

 postice radlaflm rugatd ; fidvo-ollvaced, ad iimbones 

 viridi radintd. 

 The leek-green Unio. Shell ovate, regularly convex, 

 posteriorly obtusely angular, then compressly trun- 



cated, smooth, obtusely warted in tlie middle and 

 towards the angle, posteriorly radiately wrinkled ; 

 fulvous-olive, rayed with green at the und)oes. 

 Conrad. 

 Ilab. North America. 



Mr. Lea quotes this species as being a variety of Z7. 

 Schoolcrnfttnsis. The two specimens here figured, received 

 by Mr. Cuming from a very good authority on the sub- 

 ject, Mr. Anthony, lead me to think that it must be dis- 

 tinct. There is a resemblance in colour and radiation, 

 but an important difference ill form, and in the character 

 of the sculijture. 



Species 27. (Mus. Cuming.) 



Unio fragosus. Un. testa suborbiculari, gibbosiuscutd, 

 postice obtuse angulatd, delude cornpresse expansd, um- 

 iioulbus .lubprominulis, undique promlscue tuberculato- 

 verrucosn, postice radiatd; fulvo-olivaced, viridi tinetd. 



TuE ROUGH Unio. Shell somewhat orbicular, rather 

 gibbous, posteriorly obtusely angled, then compressly 

 expanded, umboes rather prominent, promiscuously 

 tubercularly warted throughout, posteriorly rayed ; 

 fulvous-olive, tinged with green. 



Conrad, ilonog. pi. 6. f. 3. 



I.lab. North America. 



Of an orbicularly expanded form, sculptured in a pe- 



culiarlv bold and lu'omiscuous manner. 



