U N I 0. 



Plate XXII. 



Species 98. (Mus. Cumiug.) 

 Unio LITOKALIS. Uii. iesld ovatd, subaquilalerall, versus 

 ■marginem compressd, latere anlico rotundato, postico 

 decl'wi-expanso, umbonihiis snbiimpUs, olisciir? pUcato- 

 corrugatis ; liitesceiUe-oliimced, viridi /wefiri-radiadi. 

 The litoeal Unio. Shell ovate, nearly equilateral, com- 

 pressed towards the margin, anterior side roundi-ii. 

 posterior slopingly expanded, umboes rather large, 

 obscurely plicately \vriukl(.-d ; yellowish-olive, linearly 

 rayed with green. 

 CuviER, Hist. Nat. des .\.niiu. vol. i. 

 Unio crassus, Eetz. 

 Unio brevialis, Lamarck, 

 Uuio semirugala, Lamarck. 

 Uuio nana, Lamarck. 

 Uiiio subtelragona, Mieluuul. 

 Unio incurvus, Lea. 

 Unio Pianensis, Fariues. 

 Unio granosus, Schuuuieher. 

 Unio briomeiis, Bonhomme. 

 Unio Woolwichii, Morelet. 

 Unio rhoinbuiJea, Sehreibers, 

 llab. Europe. 



Of a compressed CrassatMa-Xykt: form, generally much 



Sjiecies 99. (Mus. Cuniiiii;.) 



Unio Demeuaraensis. Uv. hsld eUiptico-ovnld, hiU-n- 

 ant ICO dedivi-rotunditto, postico truncato-angulaio, con- 

 centrice denw filo-slrlalil ; nigricfinte-olivaced. 



The Demerara Unio. Shell elliptically ovate, anterior 

 side slopingly rounded, posterior truncately angled, 

 concentrically densely thread-striated ; dark-olive. 



Lea, Pro. Acad. Nat. Sci". I'hilad. IS.VJ, j). 15:2. 



Hab. Demerara. 



A sii 

 stance. 



i|)tically-trLincated shell, of ratiier 



rounded, posterior slopingly expanded, obsoletely 

 gled, umboes wrinkle-striated; yellowish-olive. 



Lea, Pro. Acad. Nat. Sci. Philad. 1850, p. 153. 



llab. Borneo. 



A shell of simple chnracter, b>it very neatly wrink 

 about the umboes with raised thread-like stri;e." 



Species 101. (Mus. Cuming.) 



o TESTIBINEUS. Un. tcstd siiboUongo-OKatd, later,' 

 anlico cuiaprcssiitscah, cunccntrice teniiilirato, postico 

 trnncato-expanso, versus uinbones obtuse artgulato ; li- 

 vido-oUvaced. 



; TORTOISE-SHELL Unio. Shell souiewhat obloug- 

 ovate, anterior side rather compressed, coneentriealiv 

 finely ridged, posterior truncately expanded, obtusely 

 angled towards the umboes; livid-olive. 



UCLirr, Moll. tcrr. et ttuv. de Port. 



. liio Usumasiuto, P<nMugal. 



he peculiar livid colouring of this species gi\cs it a 



Species 103. (.Mu,. (Aiming.) 

 10 PLICATULUS. Uii. tfsld siibcIuiKjdtii-uUungu , tcniii- 

 ciild, latere anlicu rut/mda/n. (■ui/<r,//nce liralo-sln„/o. 

 postico trnncdiii-iiriiuiiiiiitn, uxqni' ml tiiiiLitiics di'ii\f 

 divaricuto-corriii/atu ; Jl,ifc.^cc/iti'-ulimceii, niyricantc- 

 viridi interrnpli' liimiri-radiatd. 

 3 FINELY-PLAITED Umo. Shell somewhat elougalih 

 oblong, rather thin, anterior side rounded, coucentri- 

 ally ridge-striated, posterior truncately acuminated, 



Species 100. (Mus. Cuming.) 



Unio Africanus. Un. testa oblongo-ovatd, latere anticu 



rotundato, postico declivi-expianso, obsolete angulalu, 



umbonibus corrugaio-striatis ; Jlavescente-olivaced. 



The Aeuican Unio. Shell oblong-ovate, anterior side 



densely divaricately wrinkled as far 



yellowish-olive, internipli'illy linea: 



green. 

 i:a. Pro. Acad. Nat. Sci. Philad. vol. 



vol. vi. p. 20. pi. 37. f. 15. 

 lib. Cape of Good Hope. 

 AVell characterized by the finely-ili\ 

 the shell on the posterior side and ai 



; the umbi 



irk 



Species 10.3. (Mus. Cuming.) 

 catvs. Un. testa ellijitico-ovatd. Inlet 



April, 1S(J5. 



