U N I . 



Species 19 'J. 



In 10 AXATlci'LUS. Un. te-sid obliqite ornta, hrevi, cmssii, 

 tiiiiiidd, iiilits n/bd, extiis castatim, u'ujro conccntrici 

 fasciatd, latere aiitico brevissiuio, Irniiaito, latere pos- 

 tico oblique acuminato, aiigidato, ante unguium dcpres- 

 ■w, emargbialo, area post- anguliim declivi, angusfd, 

 margine ve/itrnli medio injlnto. 



The little duck's-beak Unio. Slu-ll obliiiuely-ovul. 

 short, thick, tumid, white inside, cheslmit, coiicciitvi- 

 cally banded with black outside, anterior side very 

 short, truncated, posterior side oblicpiely acuminated, 

 angular, in front of the angle depressed, eniargiiiated, 

 area behintl the angle sloping, narrow, ventral margin 

 swelled in the mid^dle. 



Lea, Unio viii. p. 90. pi. 13. f 340. 



lliib. Xear Columbus, Mississippi. 



.N'ot unlike U. eiaiu.t. Lea, but that is a larger and 



heavier species, diti'erently banded, and not quite so oblicpu'. 



The suBROTl-XD I'.vio. Shell short, subrotund. <'om- 

 pressed, thick, white inside, yellowish-brown, rayed 

 with green outside, distantly sulcated, anterior side 

 very short, angulnted near the umboes, sloping at the 

 side, ventral margin round, posterior side subobliquely 

 truncated, biangulated, depressed in front of the first 

 angle, area behind the angles sloping, narrow. 



Lea, Trans. Anier. Phil. vol. iv. t. IS. f. 45. 



Ilab. West Africa. 



Species 200. (Mus. Cuming.) 



I'xio LENS. Tin. tedd i-otuudd, crassd, s/ibcompressd, sub- 

 aqiiilaterali, intiis alba, cxtus pallide olinaced, viridi 

 subobscuraid, latere antico breviuseulo, medio tumidn, 

 latere poitico late truncato, margine dorsali declivi. 



The lens Unio. Shell round, thick, rather compressed, 

 nearly equilateral, white inside, pale-olive obscured 

 with green without, anterior side rather short, middle 

 tumid, posterior side widely truncatetl, dorsal margin 

 sloping. 



Lea, Unio, p. 90. pi. viii. f. 10. 



Jfab. River Ohio ; Lea. Tennessee; Vauuxcm. 

 A very well-named lenticular form. 



Species 201. (JIns. Cuming.) 

 o sUliUOTUNDVS. I'll, testa breci, subrotiindu, cuin- 

 pressd, crassd, intus albd, extuiifuscd-lutescenti, riridi 

 radiatd, distanter sidcald, latere antico brevissimo, 

 prope umbones angnluto, ad latus declixi, margine ven- 



tral. 



rotimdo, latere postii 

 gidato, ante angaliiin priii 

 lari declivi, angnxtd. 



nbnbliq 

 denies 



trnncnto, biun- 

 , area po-'itnnq'i- 



■ peeies 203. (Mus. Cuming.) 



Fori 



.us. Un. testa trapezoided. oblungd, 

 iiiigii.sld. crn.ssa, i/itiis albd, extusfusco-lntescente, Iftei- 

 galii,fii.s(ii\ rt I'ineis interruptis viridibus radiatd, la- 

 tere antico brcviiacnlo, siijjerne declivi, infra roluiidato, 

 margine ventral i recto, latere postico elongate, taniido, 

 truncato, biangulato, unibonihm elevatis, margine dor- 

 sali declivi. 

 Foheman's I xii.1. Shell trapezoidal, oblong, narrow, 

 thick, white inside, yellowish-green, smooth, rayed 

 with interrupted green bauds and lines outside, an- 

 terior side rather short, sloping above, rounded below. 



ventral margin 

 tumid, truncate 

 margin sloping. 



straight. 



posterior side elongati 

 ir, uuiboes elevated, dor- 



Lea, Unio 

 Uab. Coos; 



Remarkable foi 

 ilour with which 



Species 203. (Mus. Cnraing.) 

 Unio HydeaNUS. Ihi. tesld orali, solidd, iiijhild, intns 

 albd, e.vlu.i luted, radiis viridibus subdivisis ornald, la- 

 tere anticobrevi,rotu>ido,versn.s umbones angutato. medio 

 ad marginem leviler comlracto, lutere postico elongalo, 

 tumido, snbtruncato. umbonibns niagnis, injlatis, l,r- 

 vibus. 

 Hyde's Unio. Shell oval, solid, inflated, white «ithni, 

 yellow, ornamented with green, subdivided rays with- 

 out, anterior side short, round, with an angle near 

 the uuibocs, middle slightly contracted at the ventral 



