BIVALVE SHELLS. 235 



divergentibus, insequalibus, posticali longiore et angustiore ; 

 (lentibus lateralibus elongatis, angustis, acutis, striatis ; ligamen- 

 tum magnimi, crassum, subcylindricum ; impressiones musculares 

 magnae, lunulares vel circulares ; impressio pallii simplex. 



Cyrena (ex parte), Lamk. Syst. 1818. 



Corbicula (spec), Gray, Proc. Zool. Soc. 1847, p. 184. 



Batissa, Gray, Ann. Sf Mag. N. H. ser. 2. xi. 34, 1852. 



a. Species Javanicce. 



1. Batissa rotundata. 



B. testa rotundata, sublenticulari, subsequilaterali, transversim 

 rugata ; latere posteriori rugoso ; valvulis crassis ; natibus par- 

 vis, acutis, contiguis ; dentibus cardinalibus subl)iiidis ; late- 

 ralibus longis, minute serratis, rectisque; margarita alba ct 

 purpurea. 



Cyrena rotundata, Lea, Trans. of Amer. Phil. Soc. v. 107. pl. 17- 

 f. 51 ; Observ. on the Genus Unio, i. 219. pl. 17- f. 51. 



Hanley, Descr. Cat. p. 93 ; in Wood, Ind. Test Suppl. 2. 

 pl. 14. f. 55. 



Hab. Java ; insulae Philippinenses. 



2. Batissa eximia. 



B. testa ovato-orbiculari, crassiuscula, insequilaterali, transversim 

 striata, margine subrugosa; umbonibus tumidis, obliquis, haud 

 erosis, pUcis obsoletis rugulosis irregularibus ab iisdem ad latus 

 posticum decurrentibus ; epidermide atro-fusca marginem ver- 

 sus sublamellosa ; intus alba, dentibus cardinalibus in utraque 

 valva tribus, majoribus bifidis, lateralibus valvae sinistrse haud 

 crenulatis, antico valde crasso, brevi, cardine approximato, 

 dente postico remoto, longiore, subcompresso, ligamento pecu- 

 liari crasso, in dorso compresso et carinato. 



CyTcna eximia, Dunk. Zeitsch. fiir Malac. 1852, p. 51. no. 4. 



Hab. In flumine Progo, prope Mangelang, in insula Java. 



b. Species Philippinenses. 



3. Batissa Keraudrexia. B.M. 



B. testa obovata, inaiquilateraH, crassa, solida, compressiuscula. 

 maxima ; latere antico brevi, rotundato, postico latiore, superne 

 subdeclivi, anguhun obtusum ad extremitatem liganienti for- 

 mante, margine ventraU convexiusculo ; umbonibus recurv^is, 

 prominuhs, obhquis, approximatis, ssepius integris aliquantisper 

 erosis ; hgamento permagno, j^rominente cyhndraceo, postice 



