Class groups of the quadratic fields found by F. Diaz y Diaz

F. Diaz y Diaz has discovered 99 discriminants d between $- 3321607$ and $- 60638515$ inclusive for which $Q(\sqrt d )$ have a 3-rank ${r_3} = 3$. These 99 imaginary quadratic fields are analyzed here and the class groups are given and discussed for all those of special interest. In 98 cases, the associated real quadratic fields have ${r_3} = 2$, but for $d = 44806173 = 3 \cdot 14935391,Q(\sqrt d )$ has a class group $C(3) \times C(3) \times C(3)$; and this is now the smallest known d for which a real quadratic field has ${r_3} = 3$.