We propose the separation of Onslowia and Verosphacella from the Choristoca
rpaceae and from the Sphacelariales based on comparisons of DNA sequences o
f rbcL and nrRNA genes and morphological considerations. The new family Ons
lowiaceae is created to include these two genera. The families Choristocarp
aceae and Onslowiaceae are considered incertae sedis.