68 ZOOLOGY OF THE VOYAGE OF THE SULPHUR. 



Remarkable for the preponderance of the bulk of the anterior half over the 

 posterior, a circumstance which also occurs in C. bicarinata. This, however, 

 depends in some measure on the age, and is thus most conspicuous in those speci- 

 mens which may be considered as beyond adult age. 



281. Corbula tunicata, Hinds, I. c. p. 55, (Plate XX. fig. 4, 5.) Testa, ovato-trigona, obliqua, 

 antice rotundata, postice nasuta, excavata, ab umbonibus angulata; valvis insequalibus, dextra 

 praacipue maxima, valde sulcata, epidermide tenui cornea induta, sinistra prope umbonem sulcata, 

 aliter epidermide densa induta; umbonibus obliquis posticis ; intus fusca. 



Inhab. Straits of Macassar ; L'Agulhas Bank, Cape of Good Hope ; from 

 seventy fathoms, on a gravelly bottom. 



282. Corbula cuneata, Hinds, 1. c. p. 55, (Plate XX. fig. 6.) Testa ovato-trigona, aequila- 

 terali, solida, complanata, sulcata, antice rotundata, postice angulata ; valvis subsequalibus, mar- 

 ginibus ventralibus gibbosis inclausis; umbonibus rectis; intus purpurascente. 



Inhab. L'Agulhas Bank, Cape of Good Hope ; from seventy fathoms. 



283. Corbula fragilis, Hinds, 1. c. p. 56, (Plate XX. fig. 11.) Testa ovata, tenui, albida, 

 striata, striis transversis minutissime reticulata, antice subproducta, rotundata, postice elongata, ab 

 umbonibus subrotundata ; valvas dextra? margine ventrali acuta, producta ; umbonibus rectis laevi- 

 gatis, sequalibus. 



Inhab. West coast of Veragua ; from eighteen fathoms, mud. 



284. Corbula albuginosa, Hinds, 1. c. p. 56, (Plate XX. fig. 10.) Testa, retuso-ovata, tenui, 

 antice rotundata., postice subelongata, rotundata ; valvis valde disparibus, dextra longitrorsum 

 striata, pallida, margine ventrali producta, acuta, sinistra laevigata, lineis elevatis radiantibus, epi- 

 dermide fusca induta; umbonibus albidis, nitidis, insequalibus. 



Inhab. New Guinea; Straits of Macassar; from seven to twenty-two 

 fathoms, mud and coarse sand. 



285. Corbula ohesa, Hinds, 1. c. p. 57, (Plate XX. fig. 12.) Testa ovata, tenui, ventricosa, 

 pallida, striata, antice rotundata, postice ad extremitatem truncata, ab umbonibus acute angulata ; 

 valvarum marginibus ventralibus inclausis, gibbosis; umbonibus rectis, kevigatis. 



Inhab. 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. 



286. Corbula speciosa, Hinds, 1. c. p. 57, (Plate XX. fig. 7, 8.) Testa ovato-trigona, antice 

 rotundata, postice excavate angulata, albida, sanguineo dense multiradiata ; valvis valde insequalibus, 

 marginibus ventralibus inclausis, dextra rotundata, sulcata, sinistra subplanulata, striata; umbonibus 

 rectis, subplanulatis ; intus albida. 



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



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



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



assigned by M. Deshayes to a fossil species. The description also was drawn up 



