NIC— Plate XXXV. 



The small T.'mo, Shell oval, thin, rather inflated, white 

 within, green, smooth without, anterior side short, 

 round, very slightly contracted in the centre, posterior 

 side oblong, rather inflated, somewhat acuminated at 

 the end, obsc^irely biangnlated, uniboes subconcen- 

 trically undulated. 



Baknes, Silliman's Journal, vol. vi. 



Hab. Fox River, North America. 



The ridges near the umboes are nearly, but not quite, 

 concentric, or coincident with the lines of sn-owth. 



side elongated, rather broader, rather obliquely truii 

 cated, obscurely biangulated, behind the angle ob 

 seurely two-ribbed. 



Lea, Tr.ins. Anier. Thil. See. vol. v. t. 15. f. 4t. 



Ilab. Florida. 



Species 187. (Mus. Cuming.) ' 



Unio P.landingianus. Uii. testa (Mmuja, soUdd, intiis I 

 pKrpiiraarmli', extiis lavigatd, ul'wncco-fiisrd, latere \ 

 aiitico brevissi'mo, rntuiido, angudo, medio auhcontrarto, 

 latere po.ttiro elotigato, liitinsrulo. mbobliqne trutirato, 

 obscure biangulato, post anyidii„i obscure bicostato. ' 



Blanding's T'xio. Shell oblong, solid, purple within, 

 smooth, olive-brown without, anterior side very short, 

 round, narrow, middle slightly contracted, posterior , 



Species 188. (Mus. Cuming.) 



I'nio HasleuvrstiaNLS. C'/i. testd ai/g/istn, eloiigntd. 

 cum/ircssd. so/idd, itiliia piirpurnl. e.rliis nigra, latere 

 ai/tico brevissi„io, rot„mh. tiirdio xtdjcoidrarto. latere 

 poslico obscini' triiiiigididu, nd ti-ntii,ni,ii tniiicato, 

 margine dorsali arcaalo. 



Haslehurst's Unio^ Shell narrow, elongated, com- 

 pressed, solid, purple within, black without, anterior 

 side very short, round, middle slightly contracted, 

 posterior side obscurely triangulated, truncated at 

 the end, dorsal margin arched. 



Lea, Unio vii. p. i\). pi. 2i3. f. 9-\ 



Hab. Satilla liivc'r. Camden county, firorgia; C.T.Downii-. 

 A long, narrow shell, with a sliglitly-arehed np|)earauce 



and tliiek black epiihruiis. 



