230 Zoological Society. 



CoRBULA ROTALis. Corh. testd ohlongd, corned, antice rotundatd, 

 postice suhnasutd ; valvis vald"^ disparibus, dextrd prcecipue maxi- 

 md, roiundatd, sulcata, margine ventrali productd, acutd, sinistrd 

 parvd, lineis decerns elevatis radiantihus ; umbonihus valde inccqua- 

 libus, subobliquis, anticis. Long. 2^ ; lat. 1^ ; alt. 1 J lin. 

 Hab. Calapan, Mindora, Philippine Islands ; from fifteen fathoms, 

 coarse sand. 

 Cab. Cuming. 



Several species of Corbula are provided with elevated lines radia- 

 ting from the umbo of the left valve towards the ventral margin, but 

 none have them in such numbers, or so distinctly marked, as in the 

 present small species. Here they are about ten in number, and with 

 the great disparity of the valves, will readily distinguish the species. 

 Corbula polita. Corb. testd oblongd, ventricosd, tenui, albidd, 

 obsolete sulcata, antice rotundatd, postice ab umbonibus subangu- 

 latd ; valvis fer^ cequalibus, dextrce margine ventrali acutd, sub- 

 productd; umbonibus cequalibus, Icevigatis, rectis. Long. 3^; 

 lat. 2 ; alt. 21 lin. 

 Hab. Sorsogon, province of Albay, Luzon, Philippine Islands. 

 Cab. Cuming. 



Corbula quadrata. Corb. testd quadratd, albidd, tenui, Icevigatdt 

 antice rotundato-truncatd, postice rotundato-angulatd, abbreviatd; 

 valvarum marginibus ventralibus tenuibus ; umbonibus obliquis, an- 

 ticis ; dentibus parvis, gracilibus. Long. 6 ; lat. ; alt. 5 lin. 



Hab. ? 



Cab. Metcalfe. 



Corbula obesa. Co7'b. testd ovatd, tenui, ventricosd, pallida, striaid, 

 anticl rotundatd, postice ad extremitatem truncatd, ab umbonibus 

 acute angulatd; valvarum marginibus ventralibus inclausis, gib- 

 bosis ; umbonibus rectis, Icevigatis. Long. 3 ; lat. 2 ; alt. 2 lin. 

 Hab. The west coast of America, between 8° 57' and 21° 32' north 

 latitude, in from twenty- two to thirty- three fathoms, mud ; namely, 

 Panama, coast of Veragua, and San Bias. 

 Cab. Belcher. 



Corbula speciosa. Corb. testd ovato-trigond, antice rotundatd, 

 postice excavate angulatd, albidd, sanguined, dense multiradiatd ; 

 valvis valde inaqualibus, marginibus ventralibus inclausis, dextrd 

 rotundatd, sulcata, sinistrd subplanulatd, striatd; umbonibus rectis, 

 subplanulatis ; intUs albidd. Long. 9 ; lat. 5 ; alt. 7 lin. 

 C. radiata, Sowerby, Proc. Zool. Society, p. 36, 1833. 

 Hab. Panama ; from six fathoms, mud. Gulf of Nicoya, Central 

 America. 



Cab. Belcher et Cuming. 



This shell has been described as C. radiata, Sow., a name pre- 

 viously assigned by M. Deshayes to a fossil species. The description 

 also was drawn up from such an indifferent shell, that it was almost 

 by accident I discovered it was to apply to my specimens. I have 

 therefore been under the necessity of recording a new description. 



Corbula modesta. Corb. testd ovato-trigond, complanatd, pal- 



