UNIO.— Plate XLV: 



boidea, complaiiatd, epidermidefusco-Jlavesceidi indnid, 

 Mm purpurea, dentibus cardinalibus duobus el 

 denUbus liiterulihus lam'math ; latere poslico eloiigato. 

 biatii/idulu, snprn aiigulos compressd, elevatd, margine 

 recliusciilu, inter aiigidos complanato, lermino tru 

 cato, margine dorsali recto ; latere uiitico lirevinsiiiw 

 mbquudrato. 



I'ostell's Unio. Shell oblong, thick, subrhomboidal 

 flattened, invested mth yellowish-brown epidermis, 

 purple within, cardinal teeth one and two, lateral 

 teeth laminated ; posterior side elongated, with two 

 angles, above the angles compressed, elevated, margin 

 rather straight, flattened between the angles, trun- 

 cated at the end, dorsal margin straight ; anterior 

 side very short, rather square. 



Lea, Unio, vol. vi. p. 32. pi. 2G. f. 'Ji. 



lliib. Kandall's Creek, near Columbia, Georsia. 



Species 236. (Mus. Cuming in Brit.) 



Unio Laoensis. Un. testa crassd, medio compressd, ter- 

 minibus iiijlatd, reniformi, epidermide fusco-nigricante 

 indutd, intus albd, dentibus cardinalibus uno et duo- 

 bus, dentibus lateralibus laminatis ; latere poslico ob- 

 longo, margine dorsali ekvato, arcuato, lateruUter 

 declivi, lermino vix truncuto, margine dorsali medio 

 concavo ; latere autico brevi, margine ventrali rotnndo, 

 margine dorsali declivi. 



The Lao Unio. Shell thick, compressed in the middle, 

 inflated at the ends, reniform, invested with blackish- 

 brown epidermis, white within, cardinal teeth one 

 and two, lateral teeth laminated ; posterior side elon- 

 gated, dorsal margin elevated, arched, laterally slop- 

 ing, scarcely truncated at the end, dorsal margin 

 concave in the middle ; anterior side short, ventral 

 margin rounded, dorsal margin sloping. 



Lea ? MR. in Cum. Cab. 



Ilab. Camboja, Lao Mountains. 



