U N I 0. 



Species 247. (Mus. Lea.) 

 Unio bialatus. I'll, teslii sttbovali, compressd, nymplnj- 

 notd, iutus alba iridesceiiti, deiitibus lalerallbiia tenui- 

 ius, Unearibus, exliis olivaceo-viridi lavigald, latere 

 postico lalo, margine dorsali in alam latam subirigonam 

 expanso, infra alam rugis paucis magnis undato, latere 

 antico angusliore, brevi, in alam parvam cuneatatii 

 produc.to, umbonibm riigalis, hand promineutibus. 

 The bialate Unio. Shell subovate, compressed, sym- 

 pliyiiote, ii'ideseeiit-white within, lateral teeth thin, 

 linear, olive-green and smooth without, posterior siiie 

 wide, with dorsal margin expanded into a wide, 

 rather trigonal wing, beneath the wing undulated 

 with few large wrinkles, anterior side narrow, short, 

 produced into a small wedge-shaped wing, uinboes 

 rugose, scarcely prominent. 

 Lea, on Unio, vol. i. p. 59. pi. 14. f. 34. 

 Hab. Canton Eiver. 



The broad wrinkles at the base of the larger wing, be- 

 sides other characters, separate this species from U. bijla- 

 tii.i, which it otherwise somewhat resembles. 



Species '248. (Mus. Hanley.) 

 Umo Gundlaciii. Ui/. testa compressd, ovatd, iiilus 

 purpurea, deutibiis rardiimUbiis uiio et diiobns promi- 

 neutibus, creuulnlix, deiitibus /nlcriilibus posticis duo- 

 bus et una, elougalis, liiuiiualis, extus iiiiuute regulariter 

 liris concentricis rugatd, epidermide obscure fusco, 

 prope umbones radialo, umbonnm apicibus minute ru- 

 gatis, latere antico brevi, margine dorsali brevissimo, 

 angulato, margine terminali declivi, latere postico ob- 

 lique elongato, margine dorsali reetiusculo, margine 

 terminali declivi, infra subacuminato, margine ventrali 

 reetiusculo. 

 Gundlach's Unio. Shell compressed, ovate, purple 

 within, cardinal teeth one and tw^o, prominent, ere- 

 nulated, posterior lateral teeth two and one, elon- 

 gated, laminated, exterior minutely regularly wrin- 

 kled with concentric ridges, epidermis dull-i)rown, 

 radiated near the umboes, apices of the umboes mi- 

 nutely wrinkled, anterior side short, with the dorsal 

 margin very short, angular, termiiud margin sloping, 



posterior side obliquely elongated, dorsal margin 

 rather straight, terminal margin sloping, subacumi- 

 nate below, ventral margin rather straight. 



DuNKEK, Malacozoologische Blatter, vol. v. p. 228. 

 Unio persulcata. Lea. 



Hab. ? 



Species 249. (Mus. Hanley.) 



Unio Hanleyanus. Un. testa parvd, solidd, lum'utd, 

 ovali, intus alba, extus flavidd, lavigatd, projie umbones 

 conceutrice viridifasciatd, latere antico brevissimo, sub- 

 rofundo, latere postico oblique elongato, iermino acu- 

 minato, post angidum sided obliqud impresso, margine 

 dorsali subnrcuato, subdeclivi, margine ventrali ad ter- 

 miniim sursum acclivi. 



Hasley's Unio. Shell small, solid, tumid, oval, white 

 within, yellowish without, smooth, near the umboes 

 concentrically banded with green, anterior side very 

 short, rather round, posterior side obliquely elon- 

 gated, with acuminated end, behind the angle im- 

 pressed with an oblique groove, dorsal margin rather 

 arched and sligiitly sloping, ventral margin slopmg 

 upwards at the end. 



Lea. 



Hab. Georgia, North America. 



Species 25t). (Mus. Lea.) 



Unio ljjvissimus. Un. t,'s/,i or,i/„\ snbcompressd, sym- 

 phyiiolu, bialata, alls pm.tiuns. mliis rosed, extus Ice- 

 vigatd, olivaced, latere antico bn-riiafulo, margine dor- 

 sali in alam parvam expanso, latere po.itico oblongo, 

 margine dorsali in alam latam elevatam expanso. 



The veky smooth Unio. Shell ovate, subcompressed, 

 syraphynote, bialate, wings proximate, interior rose, 

 exterior smooth, olive, anterior side very short, with 

 the dorsal margin expanded into a broad elevated 

 wing; posterior side oblong, with dorsal margin ex- 

 panded into a broad elevated wing. 



Lea, on Unio, vol. i. p. 58. pi. 13. f. 23. 



Hab. River Ohio. 



More oval than the other bialate species, with the wings 



proximate, not mueli raised. 



August, 1860. 



