UNIO.— Plate LXXX. 



ventricose and biangulatod l)ehiiul, of a glossy olive 

 yellow, everywhere rayed with (tnore or less) inter- 

 rupted rays of dusky olive, smooth hehiud, but with 

 suljpliciforin concentric wrinkles anteriorly; front 

 dorsal edge the lower ; ventral margin straightish in 

 front, somewhat rising behind ; uirdjonal ridge flat, 

 double, hence biangulated at its termination ; hinder 

 area rather broad, umboes moderately projecting, 

 nacre white, primary teeth large and pyramidal, 

 lateral teeth short and prominent. 



Lea, Trans. Amer. Phil. Soc. ser. 2. vol. viii. (and Obs. on 

 Unio, vol. iii. p. 35), pi. 9. f. S. 



lloh. Cany Fork river, Tennessee, N. America. 



Conrad considers that this species is identical with his 



//t'c/orosim, which latter is referred by Lea to U. purdix. 



Species 422. (Mus. Hanley.) 

 iTRAMlNEUS. Uu. tettu oeatd, solldiiisciila, siibiii- 



aquUahrnU, aidid' breviore pomelo, d niiffuslP ro- 

 tundatd, pndice latiore et mar/U veidricosn, nltlde- 

 dramined, hand variegatd, ti'isi aUqiiando radio (noii- 

 iiiiiiqiiaiii nidih 2J viridi-crenileaci'nte supra contain. 

 iiiiihoiiiih'iii iiicoiisjiiciiaM, inid'ujiie (autici; uiitfiii max- 

 hiie) coiiccnlricL' et covfi'ii'im plicald, plwis utubonali- 

 him aiidiilatis; ijiari/iiic duraali antico hnmiUorc, ad 

 rMri'inifnleiii hand aiKjidato ; viargine venlrali v'lX 

 unbrctiiio, antlce arcnaiiiii acciici ; /imlioiiibiis satis 

 emhientibiis, natibus parvis, acntis, iniiiild i:i.r nltd, 

 angnste lanceolatd, margarild niced, denlilms cardi- 

 iialibus binis, siibtrigonis, ohliquis, Jiaud tramversis. 



The stuaw-coloured Unio. Shell ovate, rather strong, 

 not very inequilateral, shorter peculiarly projecting 

 and narrowly rounded in front, broader and more 

 ventricose behind, of a glossy straw-colour, not varie- 

 gated, except by one or two bluish-green rays be- 

 yond the inconspicuous uinbonal ridge, everywhere 

 (especially, however, in front) ridged by coucentric 

 folds, which upon the umboes become uuduliited ; 

 front dorsal edge, which is much the lower one, not 

 angulated at its extremity ; ventral margin scarcely 

 subretuse, arching upwards in front, umboes mode- 

 rately prominent, beaks small and acute, nacre snow- 

 white, primai-y teeth two in each valve, subtri.ui- 

 gular, oblique, not transverse. 



CoNKAD, Silliman's Amer. Juurn. Sc. vol. xxv. (1S:U), 

 p. 339. pi. 1. f. 6 (badly j. 



/lab. Coosa river, Alabama. 



This is not the species erroneously so termed in Plate 



•'iii. Conrad, in his ' New Freshwater Shells,' appears to 



lia\r (IcliiicaU'd it wilhout a na-nc in plate 7, f. 3. 



Species 423. (Mus. Hanley.) 



Unio lugubris. Ua. tesld validd, oblongo-subcylin- 

 draced, subrciilricosd, postice prodtictd et obtiisti sub- 

 cinieiforml, tilgro-p'u-i-d crmrolnre, lav'igatd, marghie 

 renlrati siihretiiso ft oid'ice. acclivi, costd nmlionali 

 satis coiispiciid et antiee magis minasve aiigulald, am- 

 bonibas hand eniinentibns, margariid uitidisumd vel 

 rnbro-snbpnrpnn'd, ret cnpred, dentibns cardinalibns 

 hand magnis, snbtrigunis, dentibns taleralibns prir- 

 longis, sniiarcnatis. 



The mournful Unio. Shell strong, oblong-subcylin- 

 draceons, somewhat ventricose, posteriorly produced 

 and bluntly subcuneiform, of an uniform pitch-black, 

 not sculptured; ventral margin somewhat indented, 

 rising in front ; umbonal ridge manifest, and more 

 or less angular in front; umboes not prominent; 

 nacre very brilliant, tinged with purplish-red or 

 copper-coloured, primary teeth not large, subtrigonal, 

 lateral teeth very long, somewhat curved. 



Lea, Trans. Amer. Phil. Soc. ser. 2. vol. vi. (and Obs. 

 on Unio, vol. ii. p. 30), pi. 9. f. 25. 



Hcb. Hopeton, near Uarien, N. America. 



Originally described by Lea from a single individual 



which was more elongated anteriorly than is usual. 



Species 424. (Mus. Hanley.) 

 Unio ellipsis. Un. te.dd oblique obovatd, superne soli- 

 dissiind, iiin.ame inrBqiiilateraU, aidice ventricosd, 

 postice rutundalo-angnlald et wagis depressd, laei- 

 gatd, Jlaw-olii;aced, lineis confertis oUvaceo-viridibus 

 nndique radiatd, viargine venlrali arcuato, costd um- 

 bonali inrunspii-nii, uynbonibm valde eminenfibas, re- 

 inofis. tnnulii tain, margarild albo-argodcd ; dentilms 

 cardiiKdibns (rlia.nqne l.aleralitim) perniagnis. 

 The ellii'tic Unio. Shell obliquely obovate, very solid 

 above, remarkably inequilateral, ventricose in front, 

 more depressed and rotundately angulated behind, 

 smooth, olivaceous yellow, everywhere rayed with 

 olive-green lines, ventral margin arched, umbonal 

 ridge inconspicuous, umboes very prominent and dis- 

 tant, lunule broad; nacre silvery white; both pri- 

 mary and lateral teeth very large. 

 Lea. Tr.ni?. Annr. I'll. Sue. ser. 2. vol. iii. (Obs. on Unio, 



vol. i. p. 1(1), pi. 4. f. 4. 

 hat,. Ohio, N. America. 



Such is the depth of the hinge-margin and the thick- 

 ness of the valves at the umbonal region, that the shell, 

 despite of its external tumidity, is absolutely shallow 

 within. TIic hinder primary tooth in each valve is of 

 remarkable thickn.-ss. 



