232 Entomological Society. 



CoRBULA TRiGONA. Corl). testd triffond, IcBvigatd, pallida, fused, 

 vel obsolete unifasciatd, antice rotundatd, postice abbreviatd, ab 

 umbonibus angulatd ; valvce dextrcs margine ventrali acuta, pro- 

 ductd; umbonibus rectis. Long. 4 J ; lat. 2 ; alt. 4 lin. 



Hab. Senegal. Cab. Cuming et Metcalfe. 



CoRBULA L^vis. Covb. testd ovali, cBquilaterali, pallidd, tenui, Icb- 

 vigatd, complanatd; valvce dextrce margine ventrali acutd, pro- 

 ductd; umbonibus rectis, suberosis. Long. 6 ; lat. 2 J ; alt. 4 lin. 



Hab. Hong-Kong, China. Cab. Belcher et Cuming. 



Both valves are flattened towards their ventral margins in a very 

 characteristic manner. 



CoRBULA FAB A. Corb. tcstd ovali, subcequilaterali, elevatiusculd, 

 tenui, IcBvigatd, pallide fusco tri/asciatd, postice ab umbonibus 

 angulatd; valva dextrce margine ventrali acutd, productd; um- 

 bonibus rectis, fragmentis epidermide tenui indutd. Long. 5 ; 

 lat. If; alt. 2f lin. 

 Hab. St. Miguel, east coast of Luzon, Philippine Islands. Ob- 

 tained in the mud at low water. 

 Cab. Cuming. 



It is very probable that the four species last described affect situ- 

 ations where the water is brackish rather than salt ; and though they 

 retain the hinge of Corbula, in general character they materially 

 differ from the more typical forms of the genus. 



PoTAMOMYA, J. Sowcrby. 



PoTAMOMYA NiMBOSA. Pot. tcstd ovttto-trigond, Icevigatd, antice 

 rotundatd, postice productd, angulatd ; valvis incequalibus, margine 

 ventrali acutd ; umbonibus subcequalibus ; epidermide tenui, tene- 

 brosd, indutd, lineis capillaribus radiantibus ; intus albidd. Long. 

 17; lat. 8; alt. 11 lin. 



Sowerby's Conch. Manual, f. 498, 499. 



Hab. The tributary streams of the Rio de la Plata, in the mud. 



Cab. Cuming. 



PoTAMOMYA ocREATA. Pot. tcstd valdc iucBquHaterali , antice abbre- 

 viatd, rotundatd, postice productd, subnasutd, ab umbone ad mar- 

 ginem posticam angulatd ; valvd dextrd rotundatd, margine ven- 

 trali antice productd, acutd; epidermide fused indutd; intils albidd 

 vel ccerulescente . Long. 13 ; lat. 6 ; alt. 8 lin. 



Hab. Brazil. From freshwater streams. 



Cab. Cuming et Metcalfe. 



The younger specimens are much less inequilateral than the old. 



ENTOMOLOGICAL SOCIETY. 



At the Anniversary Meeting held on the 22nd of January, Mr. G. 

 Newport, the President, delivered an Address on the state and pro- 

 gress of Entomology, from which the following interesting observa- 

 tions are extracted : — 



There is little need that I should dwell on the importance of a 



