U N I 



Species 371. (Mus. Cuming in Brit.) 



Unio geavidus. Un. testa, magna, ealde injlatd, doi/aci- 

 formi, alatd, liBvi, concentrice leviter rugatd, luteo- 

 viridi, radiis duabus viridibus posticis pictd, intus alba, 

 denfibus cardinalibiis nullis, deiitibm lateralibun /ami- 

 uatis ; latere postico late avijnlnto, marghie dona It 

 ill alani Mam elevuto, marg'me terminall trmicato, 

 margine ventraU ante unguium siirsmii acclivl, medio 

 subangulato ; latere antico brevissimo, acuminato, au- 

 gnsto, umbonibus rotuudis. 



The heavy Unio. Shell large, very inflated, wedge- 

 shaped, winged, smooth, concentrically lightly wrin- 

 kled, yellowish-green, painted with two posterior 

 green rays, white within, no cardinal teeth, lateral 

 teeth laminar; posterior side widely angular, with 

 dorsal margin elevated into a broad vving, terminal 

 margin truncated, ventral margin in front of the angle 

 sloping upwards, subangular in the middle ; anterior 

 side very short, acuminated, narrow, umboes rounded. 



Lea on Unio, vol. vi. p. 13. 



Hab. Siara. 



A large, inflated, polished shell, of a flue apple-green 

 colour. 



Species 372. (Mus. Cuming in Brit.) 



Unio lamellatus. Un. testa ovatd, ieniii, politissimd, 

 nntice olivaced, posiice viridi fasciatd et biradiatd, in- 

 tus albidd, deiite cardinali inconspicuo, dentibus late- 

 ralibus nullis j latere postico oblique angulato, termino 

 subtruncato, margine dorsali recto, margine ventrali 

 postice sursum acclivi, medio convexo ; latere antico 

 brevi, margine dorsali recto, termino rotuudo. 



The lamellated Unio. Shell ovate, thin, very po- 

 lished, olive in front, banded and two-rayed with 

 green behind, whitish inside, cardinal tooth incon- 

 spicuous, no lateral teeth; posterior side obliquely 

 angidar, truncated at the end, dorsal margin straight, 

 ventral margin posteriorly sloping upwards, convex 

 in the middle ; anterior side short, with dorsal mar- 

 gin straight, end round. 



Lea on Unio, vol. ii. t. 6. f. 1.5. 



Eab. Beng-al. 



Species 373. (Mus. Cuming in Brit.) 



Unio Pabaguayana. Un. testa ovali-stibrotundd, crassd, 

 tumidd, luteo-viridi et castaned, laevigata, intas albd, 

 dentibus cardinalihus in utrdque valvuld uno ; latere 

 postico lata, truncato, augnlato, tnai-gine dorsali ele- 

 vnto, subarcuato, margine ventrali rotunda ; latere an- 

 tico brevi, angusto, termino rotunda. 



The Paraguay Unio. Shell oval subrotund, thick, 

 tumid, yellowish-green and chestnut, smooth, white 

 within, one cardinal tooth in each valve; posterior 

 side wide, truncated, angidar, with the dorsal margin 

 elevated, rather arciied, ventral margin rounded ; an- 

 terior side short, narrow, rounded at the end. 



D'Orbigny, American Freshwater Shells. 



Hab. South America. 



A curious specie 

 form. 



ith hinge teeth of the Monocondijlea 



Species 374. (Mus. Cuming in Brit.) 



Unio capax. Un. testa rotnndata-ovali, infiatd. politd, 

 tenni, luteo-subviridi, obscure interriiptbn radiaid, in- 

 tus albd, dentibus cardinalibus magnis, irregidariter 

 serratis, dentibus lateraUbus latissimis ; latere postico 

 ablango, tumido, snperne biangiilato, margine dorsali 

 brevi, concaca, termino subtruncato, margine ventrali 

 medio rectitisculo ; latere antico angusto, brevi, mar- 

 gine dorsali brevi, concavo, termino rotunda, umboni- 

 bus magnis, rolnndis. 



The capacious Unio. Shell roundly oval, inflated, po- 

 lished, tliin, yeliowish-green, obscurely interruptedly 

 rayed, white within, cardinal teeth large, irregularly 

 serrated, lateral teeth very wide ; posterior side ob- 

 long, tumid, biangulateil above, dorsal margin short, 

 concave, the end subtruncated, ventral margin rather 

 straight in the middle ; anterior side narrow, short, 

 dorsal margin short, concave, rounded at the end, 

 umboes large, round. 



Green, ? 



Hab. United States. 



This splendid shell is remarkable for the large size of 



the umboes and shortness of the somewhat concave dorsal 



line. 



November, ISOfi. 



