UNIO.— Plate LXI. 



The inflated and somewhat alate posterior side gives 

 this shell a different aspeet lo that of TJnio rar/ialus, 

 Lamk. 



Species 307. (Mus. Sowerby.) 



Unio AFFlNls. Uii. tesld taimi, ovatd, paUide oUvaced, 

 laviyatd, obscure Jlavidd, lineis viridibm angmtis 

 postice et antlce crebris, medio distantibus radiatd, 

 intus salmoned et carulescenti, dc.ntibm cardmalibus 

 rompresm et laceratis ; latere postico lata, obscure 

 binngulato, super et post angulos coHceuirice rugalo, 

 marghie dorsali elevato, area postaiigularl compressd, 

 siihalatd, margine veutrali iiiflato, umbonibus perubli- 

 qnis ; latere antlco brevi, angustalo. 



The related Unio. Shell thin, ovate, pale olive, 

 smooth, (Itdl yellow, rayed with narrow green lines, 

 which arc close before and behind, and distant in the 

 middle, salmon and bluish within, with cardinal 

 teeth compressed and jagged ; posterior side wide, 

 obscurely biangidated, concentrically wrinkled upon 

 and liehind the angles, dorsal margin elevated, post- 

 angular area compressed, subalate, ventral margin in- 

 flated, uniboes veiy oblique ; anterior side short, gra- 

 dually narrowed. 



Lea, Obs. on Unio, vol. v. p. 27. pi. 19. f. 3(5. 



Hab. Alexandria, Louisiana ; l)r. Hall. 



produclo, oblique biangulalo, acuininato, subrostrato, 

 margine ventrali ante a,ngulum concave, versus medium 

 convexo ; latere antico brevi, supra obtuse cuneato. 



Vaughan's Unio. Shell elongated, rather thin, rather flat, 

 olive, smooth, bluish-white within, cardinal teeth two 

 and one, compressed, ragged, lateral teeth two and 

 one; posterior side produced, obliquely biangular, 

 acuminated, subrostrated, ventral margin concave in 

 front of the angle, convex towards the middle ; an- 

 terior side short, obtusely cuneate above. 



Lea, Obs. on Unio, vol. ii. p. 28. pi. S). f 23. 



linb. Sawney's Creek. 



Species 308. (Mus. Sowerby.) 

 Unio Vaughanianus. Uu. testa clongatd, tenuiMsculd, sub- 

 comphnrdd, olivaced, lavigata, intus albido-cceruled, 

 deultbus r/irdi)iidibiiK dnnbus et nno, compressix, lacera- 

 tis, lukralibuH diiobus H nno laininalis ; latere postico 



Species 309. (Mus. Taylor.) 



I'nio lineatus. Vn. tesld subcuneiformi, altd, injiatd, 

 solidd, politd, riridi-flaveseenti, lineis distantibus, vi- 

 ridi-nigrescenlilms radiatd, intus laded ; latere pos- 

 tico elevatim angulato, lato, oblique subquadralo, miir- 

 gi.ne ventruU wquaUter convexo, wnbonibus undulatis, 

 proniinentibus ; latere autico hrevi, angustiore, ante 

 nmbones excavalo. 



The lineated Unio. Shell subeuneiform, elevated, 

 inflated, solid, polished, greenish-yellow, rayed with 

 distant blackish-green lines, white within ; posterior 

 side with an elevated angle, wide, obliquely sub- 

 quadrate, ventral margin equally convex, with um- 

 boes undidating, prominent ; anterior side short, ra- 

 ther more narrow, excavated in front of the umboes. 



Lea, Obs. ou Unio, vol. iii. p. 44. pi. 13. f. 20. 



Hab. Chattahoochee river, Cohinibus, Georgia; Dr. 

 Bovkiu. 



