20 CATALOGUE FAMILY UN1OMILK. 



f Unio appressiis, Lea. 



; vations on the Gmus Qnio, Vol. Kill. PI. III. Fig. s.i 



Tennessee and Ilolston rivers, at and above Tuscumbia, Alab;iiJia and easi 

 Tennessee. 



| Unio approximiis, Lea. 



(Trims. Am. Phi'. Soc., :M Scries. Vol. X, PI. V. Fig. i:*... 



Red River, Louisiana. This is a member of the lutcoln* gronp: it is ven 

 close to IT. hydianus, Lea. 



f Unio arca'formis, Lea. 



(Trans. Am. Phil. Six-., Vol. IV. P . XVII. Fig. 44.) 



Clinch, Ilolston and Cumberland rivers, Tennessee, the last named being the 

 original locality. 



t Unio arctior, Lea. 



(Trans. Am. Phil. Foe., Vo'. VI, PI. IV, Fi-. 10.) 



Ohio and Coosa rivers. This so-called species is synonymous with U. gil>- 

 hosus, Barnes, from the type of which it differs only in the white nacre. 



t Unio argeiiteiis, Lea 



(Trans. Am. Phil. Soc., ^nd Series, Vol. VIII, PI. XXV, Fi. 57.) 

 Holston river and Conasanga Creek, east Tennessee, and Armuchee and 

 Swamp creeks, northwest Georgia. This species is a member of a very numer- 

 ous group illustrated by U. rjldndaceus, U. verus, U. infttructux. U. oviform ix. 

 U. estabrooManus, U. troschelianus&RA others. This, together with the rnbiy- 

 iiwsus, cla-vns and novi-eboraci groups, presents a very considerable portion of 

 the synonomy of our UH'IOUC*. 



\ Unio arkaiiKCiisis, Lea. 



(Jour. Acad. Xat. Sci. Phil., r<l Series. Vol. V., F'l. XXX, Fig. :.'7. ; ',.) 



"Hot Springs, Arkansas." This is the only information at present attainable 

 regarding this species, which appears to be rare. 



I Unio ar<]iia1 us, Conrad. 



i Figured ?i 

 "Wabash River, Indiana." No specimens have passed under notice. 



f'ATAUWUK \'l. 



