UNIO.— Plate XC. 



each valve ; lateral lamella; strong, produced, slant- 

 ing. 



l.EA, Journ. Ac. Nat. So. Philad. ser. 2. vol. iii. (Obs. on 

 Uiiio, vol. vi. p. 281, pi. 29. f. 23. 



Rab. Kio Plata and Rio Negro, S. America. 



Species 488. (Copied from Lea.) 



Unio favosus. Tin. tesii crasnd, depresdmcu.ht, lati 

 ovali, siibinaquilateraU, postice subbiauyulald, stipenie 

 Icevl, infei'ne coucenlrice striata, saturalius olivaceo- 

 Itifea, maciilarum viridium serie unicd ante costa/n nui- 

 bonalem snbrotundatam ornatd ; maryine veiitrali ur- 

 cuato ; lunula vel nulla, vel iticouspicud ; natibus pro- 

 mmidis, ad apices uiidk snbrudibus 2-3 ornatis, mar- 

 garild alba; dentibus cardinalibus mayuis, ereclis, 

 pyi-amidalibm, crenulatis, in valvuld sinislrd 2 ; la- 

 nieUis lateralibiis productis. 



The honey-combed Unio. Shell thick, somewhat de- 

 pressed, broadly oval, somewhat inequilateral, sub- 

 biaiigular behind, smooth above, concentrically stri- 

 ated below, dark olive-yellow, with a single row of 

 broad spots before the somewhat rounded umbonal 

 ridge ; ventral edge arched ; lunule, if any, not con- 

 spicuous ; beaks a little projecting, adorned with two 

 or three rather coarse undulations, nacre white ; pri- 

 mary teeth large, erect, pyramidal, two in tlie left 

 valve ; lateral lamellaj produced. 



Lea, Journ. Ac. Nat. Sc. Philad. ser. 3. vol. iv. (Obs. on 

 Unio, vol. vi. p. 58), pi. 8. f. 40. 



llab. Othcalooga Creek, Georgia, America. 



The Javanese Unio. Shell thickish, subventricose in 

 the middle, very inequilateral, subovate, sloping up- 

 wards in front below, depressed and subbiangular 

 behiiul, smooth, shining, of a uniform yellow-brown ; 

 beaks scarcely prominent, nacre white ; primary teeth 

 very small, single in the right valve ; lateral lameUse 

 long, curved. 



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

 Unio, vol. iii. p. 58), pi. 18. f. 37. 

 U. iiiuiatns, Mousson, teste Philippi. 



Ilab. Java. 



The colour is said to be very dark on the hinder dorsal 

 slope, on which arc de|)ieted some oblique diverging 

 wrinkles. If Philippi should be right as to its identity 

 with viutalas, the colour of the epidermis should be green 

 or olivaceous. 



Species 489. (Copied from Lea.) 

 10 Javanus. Un. testa crassiusculd, in. medio subven- 

 Irivosd, valde inaquilaterali, subovatd, anlice inferm 

 acclivi, postice depressd et subbianyulatd, Icevi, nitidd, 

 J'usco-lutesceute concolore; natibus mxprominiilis, mar- 

 yuritd alba ; dentibus cardinalibus perparvis, in val- 

 i-uld dexlrd sinyulis ; lahiellis lateralibus lonijis, 

 rurcatis. 



Species 490. (Copied from Lea.) 

 Unio rubellianus. Un. testa parvd, mayis minusve 

 crassd, siibventrieosd, elonyato-oblonyd, inferne late in- 

 curvatd, postice subattenuatd anyulatd et plicis parvis 

 divergentibus instructd, alibi laviyatd, rubella, obsolete 

 radiatd, costd umbonali anyulatd ; natihis eminent ibus 

 et sparsim irreyulariter undulatis, maryaritd auran- 

 tio-rubru; dentibus cardinalibus parvis, ereetis, aeutis; 

 lamellis laterulibus rectiuscuUs. 

 The buddy Unio. Shell small, more or less thick, sub- 

 ventricose, elongated-oblong, broadly incurved ven- 

 traUy, somewhat tapering angular and marked with 

 small diverging folds behind, elsewhere smooth, red- 

 dish, with indistinct rays; umbonal ridge angular; 

 beaks prominent, with a few irregular undulations, 

 nacre reddish salmon-colour; primary teeth small, 

 erect, sharp; lateral lamellae straightish. 

 Lea, .Journ. Ac. Nat. Sc. Philad. ser. 2. vol. iv. (Obs. on 



Unio, vol. vi. p. 70), pi. 13. f. 51. 

 Hab. Othcalooga Creek, Georgia, America. 



" The rays are indistinct, and arc formed partly by ob- 

 scure arrowiu-ad or zigzag markings, which are plainer 

 on the posterior half." 



