230 Zoological Society. 



CoRBULA ROTALis. Corb. testd oblongd, corned, antice rotundatd, 

 postice subnasutd ; valvis valde dispnribus, dextrd j)rcecipue maxi- 

 md, rotundatd, sulcata, margine ventrali prodvctd, acutd, sinistrd 

 parvd, lineis decerns elevatis radiantibvs ; wnbonibus valde incsqua- 

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

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

 coarse sand. 

 Cab. Cuming. 



Several species of Corbula are provided w^ith 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 mai'ked, 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'k ccqualibus, 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, Iccvigatd, 

 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. Corb. testd ovatd, tenui, ventricosd, pallida, striatd, 

 antice rotundatd, postice. ad extremitatem truncatd, ab umbonibus 

 acute angulatd; valvarum marginibus ventralibus inclaiisis, gib- 

 bosis ; umbonibus rectis, Itevigatis. 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, densi multiradiatd ; 

 valvis valde incequalibus , marginibus ventralibus inclausis, dextrd 

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

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

 C radiata, Sowerby, Proc. Zool. Society, p. 3G, 1833. 

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

 America. 



Cab. Belcher et Cuming. 



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

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

 also was drawn uj^ 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. testa ovato-trigond, complanatd, pal- 



