U N I 0. 



Plate XXV I II. 



Sptek-s 1-KJ. (Miis. Cuming. I 

 Uxio Menkianus. Uii. tedd oblongn, coiiipressiiiscnht, 

 umboiiibiis co7-n<gatis, latere aiiiico brcvi, rotiuidalo, 

 postico subqiiadrato-producio, rotmiihilo -. hilescente, 

 paUide viridi radintd. 

 Menke's Unio. Shell oblong', ratliei- coinprcssed, um- 

 boes wrinkled, anterior side ^luirt. rnumk'd, poste- 

 rior somewhat squarely produced, ruuudcd, yellow- 

 ish ; rayed with pale green. 



Phil. Soc. 183fi : Obs. vol. 



pi. 19. f. 50. 

 Hub. Tennessee, North America. 



Of a characteristic yellowish tone of colour, the green 

 rays being correspondingly bright. 



Species 141. (Mus. Cuming.) 



I N'lo DIMINUTUS. Un. testd subatii/HStt' ovntd, compressd, 

 vndique pecuUariter crispato-corritgatd, latere antico 

 declivi-rotundato, postico subattenuato, superne obscure 

 fexHoso-angulato ; ustulalo-fulvd. 



The small Unio. Shell rather narrowly ovate, com- 

 pressed, everywhere peculiarly crisply wrinkled, an- 

 terior side slopingly rounded, posterior slightly at- 

 tenuated, obscurely flexuously angled at the upper 

 part ; burnt-fulvous colour. 



Lea, Pro. Acad. Nat. Sci. Phil. 1859, p. 1.">1 ; Obs. vol. viii. 

 p. 72. pi. 39. f. 134. 



Hab. East Africa. 



A very distinct form of Unio, in which the surface is 



peculiarly crisply wrinkled throughout. 



Species 143. (Mus. Cuming.) 

 I NIO SuMATRENSIs. Un. testd suhlrigono-oblongd, temd- 

 ciild, undique tenue crispalo-corrugatd, latere antico 

 attenuato-rotundato, postico declivi-truncato, gradatim 

 latiore, obscure titmido-angulato ; fulveseente-olivaced. 

 The Sumatra Unio. Shell somewhat triangularly ob- 

 long, rather thin, finely crLsply wrinkled throughout, 

 anterior side attenuately rounded, posterior slopingly 

 truncated, gradually broader, obscurely tumidly an- 

 gled ; fulvous-olive. 



Lea, Pro. Acad. Nat. Sci. 1859, p. l.^S; Obs, vol. v 



p. 57. pi. 34. f. 118. 

 Hab. Sumatra. 



The scidpture of this species resembles that of the pr 

 ceding in some measure, but it is nuicli less prouiinent 

 developed. 



Species 143. (Mus. Cuming.) 



Unio apl.atUS. Un. testd ovato-oblongd, nwdice conre.rd. 

 licvigatd, valde iiueq/iilalerali, latere antico atteiiiinto- 

 rotundato, postico subtriincato-rotundatd ; piced. 



The flattened Unio. Shell ovately oblong, mode- 

 rately convex, smooth, very inequilateral, anterior 

 side attenuately-rounded, posteriorly slightly truu- 

 cately-rounded ; pitch-black. 



SwAiNsoN, MS. in Mus. Cuming. 



Ilrib. Island of Chiloe, Chili; Cuming. 



A species of simple character, with somewhat of iho 



general external aspect of a (Slyvimcris. 



Species 144. (Mus. Cuming.) 



Unto nitens. Ua. testd elliptico-oblongd, medio siibcom- 

 pressd, concentrice rude striatd, latere antico declin- 

 rotmidato, postico arcuatim truncato-anguhdo ; fusro- 

 oUvdced. 



The SHINING Unio. Shell elliptically oblong, slightly 

 compressed in the middle, concentrically rudely stri- 

 ated, anterior side slopingly rounded, posterior areu- 

 ately truncately angled ; fuscous-olive. 



Lea, Trans. Amer." Pliil. Soc. 1840; Obs. vol. iii. p. 4:). 

 pi. 13. f. 19. 



JIab. Tennessee, North America. 



Distinguished by an arcuate tlcxuous aiigulaticjn nf tlie 



upper posterior side. 



Species 145. (Mus. Cuming.) 

 Unio MEllDlfiKlt. Un. ledd ovato-oblongd, gibboso-con- 

 vexd, medio subcompressd, concentrice rude striata, ta- 

 teribus rotundatis, postico obscure trnncato-angulatv ; 

 piced. 



June, 1865. 



