BIVALVE SHELLS. 236 



divergentibus, inaequalibus, posticali longiore et angustiore ; 

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

 tum raaguum, crassum, subrylindricum ; impressiones musculares 

 raagnae, luuulares vel circulares ; im])ressio pallii simplex. 



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



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



Batissa, Gray, Ann. S)- 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 ; deatibus cardinalibus subbifidis ; late- 

 ralibus longis, minute serratis, reetisque ; margarita alba ct 

 purpm-ea. 



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

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



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

 pi. 14. f. 55. 



Hab. Java; insulse Philippinenses. 



2. Batissa eximia. 



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

 striata, margine subrugosa; umbonibus tumidis, obliquis, baud 

 ei'osis, plicis 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 valvaj sinistrse baud 

 cremdatis, antico valde crasso, brevi, cardine approximate, 

 dente postico remoto, longiore, subcompresso, ligamento pecu- 

 Uari crasso, in dorso compresso et carinato. 



Cyrena eximia. Dunk. Zeitsch.fur Malac. 1852, p. 51. no. 4. 



Hab. In flumine Progo, pi-ope Mangelang, in insula Java. 



b. Species Philippinenses. 



3. Batissa Keraudrenia. B.M. 



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

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

 subdeciivi, angulum obtusum ad extremitatem ligamenti for- 

 mante, margine ventrali convexiuscido ; umbonibus recurvis, 

 prominulis, obliquis, approximatis, saepius integris aliquantisper 

 erosis ; ligamento permagno, prominente cylindraceo, postice 



