U N I 0. 



Species 3i;0. (:\Iiis. llaiiley.) 



Unio coitRUGATUS. Uii. lesld parvd, riri//i, snhvc-ntri- 

 ■■usd, mar/is miiiiisve ovcdi, vix inaqidlutendi, ItErigatd, 

 porcis auteiii Uiicnrihrn ohlh[nh utdes versus emiiieidi's 

 mibr(id[(dd ; iiiargiiie dormli vix dcclivi, aidiw con- 

 cava ; Mitn/inc reidraJi convc.ro ; Itinidd didiiicld, 

 iiinrijantd idh'uhi, di-ntibiix curdhialihua validis, hwi- 

 iiintis himl hn,ii„idis. 



The wrinkled Unio. Shell small, green, subveutricose 

 (but varying in shape from elliptic to rounded oval), 

 scarcely inequilateral, smooth, except near the pro- 

 minent beaks, which are adorned with somewhat ra- 

 diating, oblique, linear ridges ; dorsal edges not 

 much sloping, the front one concave ; ventral margin 

 convex ; lunule well marked, nacre nearly white, 

 cardinal teeth strong, jagged, not lamellar. 



Chemnitz {Mi/a), Conch. Cab. vol. vi. pi. 3. f. 33. 

 Mya spuria, Gmelin. 



Ilab. Coromandel, etc., East Indies. 



Mullcr's description of his 21>ja comgata must have 

 lieen taken fVom very young individuals. The shells de- 

 lineated by Chemnitz and Wood evidently belong to this 

 species. It is more than probable that the U. Wyuetjun- 

 geu-iis of Lea is a transverse form of this variable species. 



Species 361. (Mns. Hanley.) 



Unio Forbestanus. Uh. tcstd pared, ohloiigo-subquad- 

 rald. ii,il.< ',,,/■, ' ii'i/iii, niticlu, subl/evigatd, pos- 

 tirr s/i/irr ■ , /' ,- ',-olivaced, rudiis angitstis vi- 



ridi-nlir,h , i-^ iii,,:i,rr niiigis coiispicuisj orimld, area 

 pQsticd exireiiui riigis elmatli obliquis sparsiiii scidptd; 

 murgiue ventrali valde convexo, a/dice acclivi, lunula 

 incouspicud, margaritd alhidd, deulibus cardinalibus 

 validis. 



FoRBEs's Unio, Shell small, s(|uarish-oblong, decidedly 

 short in front, not thick, glossy, subvenlricose be- 

 hind, yellowish-olive, with narrow rays of olivaceous 

 green, which are more conspicuous posteriorly, 

 smooth, yet with raised oblique wrinkles behind the 

 umbonal ridge ; ventral margin curved, rising in 

 front, lunule iiiconspicuous, nacre whitish, cardinal 

 teeth strong. 



Le.\, Obs. on Unio, vol. v. p. 20. pi. Ifi. f. 17. 



llab. Savannah river, North America. 



The uraboes are eroded, and not prominent, the troiit 

 extremity is rounded, the hinder termination bluntly biaii- 

 gulated, the hinder dorsal edge straightish and scarcely 

 sloping, the nacre iridescent, and the umbonal ridge con- 

 spicuously angled. 



Species 3B2. (Mns. Hanley.) 

 Unio N.aTALENSIS. Un. testa parvd, doiigulo-ohtmigii. 

 coiiipressinscidd, sijiiaUde flavo-olivaced, Itand radudd, 

 riigis devalis nidibiis irregidaribns (atdice conferliori- 



igisijn 



itlis, postici latioribiis magisqiie obs> 



Itdis) nudiqne co/iceidrici' scidptd ; margine ventrali 

 subrdaso ; dentibus curdiiudibus hatid lamiuatis. 



The Nat.vl Unio. Shell small, elongated-oblong, some- 

 what compressed, dirty olivaceous-yellow, not rayed, 

 concentrically sculptured throughout with coarse and 

 irregular raised lines, which are sharper and closer 

 in front, broader and more flattened behind ; ventral 

 margin slightly retuse ; cardinal teeth not lamellar. 



Lea, Proc. Philadelph. 1864. 

 ! Hab. Natal, South Africa. 



I The whitish nacre is stained with olivaceous yellow in 

 I the uMi-e r(ni(M\c |Hirii.iii ul' tlir interior. The valves are 

 j not tliiek,llie anttrior bide is decidedly short and rounded 

 i at its extremity, the posterior end is rotundately subbiau- 

 [ gulated, and the broad and flattened umbonal ridge is 

 ' succeedeil by a distinct though shallow groove, and :i 

 second, though very faint one, beyond it. 



Species 363. (Fig. a, b, Mns. Hanley.) 

 Unio RETUSUS. Uu. testa ulld, snhcordido-jiijrinuiilali, 

 solidissimd, siiblffvigutd, rvgis iucn-uhtdi Imdiini snb- 

 plicatu, olivaceo-jlavesreide (aidicv saqiiiis satiiridwn-, 

 i.e. fusco-idgresceide) , hand radialu, latere aidiai per- 

 breci, rotandalo, coiiipressiuscido ; inargine veidrnli 

 valde arcuato ; uatibus ma.rime emiiii'tdibus aidrorsui/i 

 incUnatis, margaritd piirpiired, deidib/is cardinidibns 

 permaguis, laciniatis, pgraiiddidib/is. 

 The blunt I'nio. Shell somewhat heart-shaped j)yra- 

 luidal, higher than broad, very solid, smooth, except 

 for the plieiforui ridges of increase, of an olivaceous 



-March, 1S6S. 



