UN 10 



Species 223. (Mii^. Cuuiiug.) 



Unio FiBUl.oiDES. U/i. U's/d pf'iTii, x/ibro/iiii'/ii, crami, 

 heoigalii, iiiliis alba, exiiis liitesrciitf, hili'rf aiitiro 

 brevimmo, rectimculo, i,iargiiii' reiilruli rulmiilo, la- \ 

 lere posllco obscure angntatu, manjutihus durscdi d 

 latero-dorsali arcuatis. 



The button Unio. Shell small, rather round, thick, 

 smooth, white within, yellowish without, anterior 

 side very short, rather straight, ventral margin round- 

 ed, posterior side obscurely angular, dorsal and latero- 

 dorsal margins archetl. 



Lea, Unio vii. p. 37, pi. xxviii. f. 100. 



Hah. Counasuaga lliver, Georgia. 



Mr. Lea remarks of this interesting little species that 



it is more orbicular in Ibrm than either U. vnrli-opsia or 

 U. Tnchelianus. 



Species 234.. (Fig. a, b, Mus. Cuming.) 

 Unio Ntass^K. Un. testa oblique cutieatd, solidd, pa-slice 

 oblique angulutd, inl'is alba, extus olivnrni, iiilnite, 

 m/'dio et prope nmbtnies minute augitlalii:! nigahi, 

 latere antico breoissiuio, margine vrulra/i anliir in- 

 flato, poslice suhcoiicavo, latere postico ad terniinihii 

 ncumiuato, m.argiiie dorsali bred, recto, margine dorxo- 

 lalerali obliquo. 

 The Nyassa Unio. Shell obliquely wedge-shaped, solid, 

 posteriorly angular, white within, olive, shining with- 

 out, with minute angular wrinkles in the middle and 

 near the umboes, anterior side very short, ventral 

 margin swelled in front, and slightly concave be- 

 hind, posterior side acuminated at the end, dorsal 

 nuu'gin short, straight, dorso-latcral margin oblitpie. 



SoWEUliV. 



Hab. Lake Nyassa. 



The several speciuicns of this shell in the cullectioii of 

 the late Mr. Cuming differ from each other in form, the 

 two specimens figured Ijcing both more oblique than one 

 remaining unligurcd, and one of them being much more 

 <'Xtensivc!v wrinkled than the other. 



crassd, iulus alba, margarilaci'd, extus rugosd, olivaceo- 

 J'uscd, obscurl} radiatd, prope unibones uudulatim ru- 

 gatd, latere antico brevi, subrolundo, tumido, margine 

 ventrali aniice injlali), poslice exracatn, latere postico 

 angnstalo, drprr.s.s,,. ad Ivruiiuin,, nbsruri triaiigidalo, 

 margine dorsali deelivi. 

 The Valentia Unio. Shell rather compressed, oblong, 

 thick, white and pearly within, rough, olive-brown, 

 obscurely rayed without, wavily wrinkled near the 

 umboes, anterior side short, rather rounded, tumid, 

 ventral margin inflated in front, excavated behind, 

 posterior side narrow, depressed, obscurely triangular 

 at the end, dorsal margin sloping. 



SOWEIIBY. 



Hah. Valentia, Spain. 



Several specimens of this species have been kindly r(nn- 

 municated by A. Harrison, Esq. 



Species 230. (Mus. Cuming.) 



Unio Cafeer. Un. testa angustu,oblongd, tenui, injlatd, 

 intus lutesceute, extus suhlavirjatd, sordide olivaced, 

 latere antico breriusmln, siibnduudo, margine ventrali 

 recto, vix medio cmttracto, latere postico oblongo, ob- 

 scurissime hiangulalo, margine dorsali redo, margine 

 latero-dorsali subarcuatim declici. 



The Caefeu Unio. Shell narrow, oblong, thin, inllatcrl, 

 yellowish within, rather smooth, dull-olive without, 

 anterior side rather short, rather rounil, ventral mar- 

 gin straight, very slightly contracted in the middle, 

 posterior side oblong, very obscurely biangidar, ilorsal 

 margin straight, latero-dorsal margin rather archcil, 

 sloph^g, 



Krauss, Smlaf. ^loll. p. 18. t. i. f. \\. ■ 



Hab. Natal. 



Species 225. (Mus. Harrison.) 

 Unio Vai.entiaNUS. Un. testa subcompressd, ohlongd. 



Species 227. (Mus. Cuming.) 

 Unio Bujisvensis. Un. testa eompressd, laid, solidd, 

 reel,!, iulus albidd, extus litvigatd, luted, viridi ra- 

 diatd, latere aulieo brevissinio, deelivi, margine ventrali 

 paulii eourexo, latere postico oblongo, subquadrato, ob- 



May, IS 00. 



