Cytherea alternata. Cyth. testd subrotundato-trigond, lineis con- 

 centricis elevatis acutis frequentibus ornatd, albd spadiceo radiatd ; 

 ared dorsali vel posticd lunuldgue spadiceo-vįolaceis ; inius albd, 

 umbones versus spadiceo-violaceo obscure nebulosd ; limbo interno 

 Icevi: long. 1"4, lat. 0"8, alt. \2 poli. 

 Hab. ad Columbiam Occidentalem. (Monte Christi.) 

 This species was dredged up in sandy mud at a depth of seven 

 fathoms. The size of the specimen is rather less than that of the pre- 

 ceding. — W. J. B. 



Cytherea tortuosa. Cyth. testd oblique cordatd,postice sublobatd, 

 lineis frequentibus subconcentricis obtusis pąstici irregularibus, 

 albd umbones versus subspadiceo-albd : long. 16, lat. 0-85, alt. 

 1-2 poli. 



Hab. ad Panamara, et ad Xipixapi. 



Var. testą roseo rufoąue pulcherrimė subradiatim pictft. 



Lamarck refers to no figure for his Cyth. albina, but only says that 

 it has some likeness to the Pectunculus figured in Lister's Conchology, 

 t. 263, /. 99. Part of Lamarck's description would apply to the 

 shell now before me, but the term " striis exiguis" is inapplicable to 

 the blunt and coarse lines with which the shell nnder description is 

 marked concentrically, and as there is no notice taken of the posterior 

 sublobation, I mušt conclude that Lamarck's Cyth. albina is not my 

 Cyth. tortuosa. 



Dredged up from sandy mud at a depth of six fathoms. — W. J. B. 



Cytherea affinis. Cyth. testd ovafo-oblongd, planiusculd, lineis 

 distantibus elevatis subacutis concentricis, albente violaceo ra- 

 diatd, posticd vix suhlohata ; ared posticd violaced, lunuld pallidd ; 

 intiis albd, limbo interno Icevi; epidermide fuscd tenui : long. 16, 

 lat. 0-7, alt. I- 1 poli. 

 Hab. ad Colombiam Occidentalenl. (Xipixapi.) 

 This species, which approaches the lašt, difFers from it in the fol- 

 lowing particulars. The shell is much flatter, the elevated, regular, 

 concentrie, somewhat sharp lines are much more distant, (especially 

 as they recede from the umbones,) than the irregular, close-set, blunted 

 lineations, almost amounting to rugosities, of Cyth. tortuosa. There 

 is an approach to lobation towards the dorsal or posterior border ; 

 but it is not nearly so strongly marked as in Cyth. tortuosa. Still it 

 may be a varlety of Cyth. tortuosa. 



Dredged up from sandy mud at a depth of ten fathoms. — W. J. B. 



Cytherea Dione, varr. 



Though varieties of this species have, for a long time, been kno\vn 

 in this country, I am not aware that they have ever been recorded. 

 The descriptions of Linnseus and Lamarck and the figures ąuoted by 

 them, apply to the variety found in the "VVest Indies, which is com- 

 paratively small with the lamella high an^ sharp and the spines close- 

 set and short, the prevailing tinge of the shell being of a some-vvhat 

 vinous or purplish flesh-colour. A dark-coloured long-spined variety of 

 this and a vvhite one, also •vvith long spines, the spines in both being 

 very close-set, were dredged up from sandy mud at a depth of nine 

 fathoms at Salango in West Colombia. 



