Hello Flavio, The Mitra on your website appears to be Mitra nubila Gmelin. The listed locality would support that. The two Vexillum specimens are both members of the regina/filiareginae/citrinum complex, a rather confusing group. I would call the one with the black spiral line Vexillum regina Sowerby, form filiareginae Cate. The other one could be the same, or a related species. The Tellina looks like Tellina radiata L. On which coast of Mexico is the listed locality located? If it is on the Caribbean side, then I'd go with Tellina radiata. Regards, Paul M.