480 REV. ET MAG. DE zooLOGiE. (De'cembre 1862.) 



decurrentibus plus minusve fimbriatum, margine colu- 

 mellari calloso. Operculum corneum, pellucidum, tenue, 

 subtiliter et concentrice striatum, fulvo-rubellum. 



Longit. 24, diam. 9 mill. 



Hab. Canton. 



UNIO iMPERULis. Testa magna, crassa, ponderosa, 

 modice tumida, late ovalis, transversim lamelloso-rugata, 

 epidermide castaneo-nigricante vestita, antice breviter 

 rotundata, postice latior et truncata, sulcisque duobus 

 obsoletis radiata ; margo superior in alam compressam, 

 ligamento connexam, dilatatus ; umbones mediocres, de- 

 pressi, late decorticati; laminae et denies validi, promi- 

 nentes; dens in valva dextra pyramidato-triangularis, in 

 sinistra crassus, bipartitus, ruditer sulcatus et crenulatus; 

 impressiones musculorum profundae ; margarita alba, 

 pulcherrime iridescens. 



Altit. 141, latit. 197, diam. 86 mill. 



Hab. in paludibus prope fluvium Meinam. 



U. ABNORMIS. Testa subrhomboidea, valde inaequi- 

 lateralis, tumida, tenuis, irregulariter striatula, antice at- 

 tenuata, subtruncata, postice late rotundata, margine 

 supero subhorizontali, in alam brevem, compressam, di- 

 latato, basali antice ascendente; epidermis parum niteus, 

 ochraceo-virescens, postice viridi-radiata : umbones in- 

 flati, fere integri, subcordiformes : laminae cardinales 

 compressae, acutas, tenues ; denies in lamellam tenuem 

 compressam, brevem, margini subparallelam, in valva 

 sinistra inaequaliterbifidam, transeuntes ; margarita albo- 

 caerulescens. 



Altit. 59, latit. 48, diam. 38 mill., 



Hab. Bangkok. 



CYRENA (Batissa) PRIMEI. Testa transversim ovata, 

 subaequilateralis, tumidula, lateribus rotundata, solida, 



nilida, sulcis numerosis et tenuibus regulariter coelata, 

 epidermide viridi-lutescente, ad umbones fuscescente, 

 induta, maculisque paucis fusculis obscure notata ; unibo- 

 nes obtusi, erosi, antice vixproni; ligamentum tumidum, 



