Bell toad and Toad frog

Bell toad noun - Western North American frog with a taillike copulatory organ.

Toad frog and bell toad are semantically related. In some cases you can use "Toad frog" instead a noun phrase "Bell toad".

Toad frog noun - Any of various tailless stout-bodied amphibians with long hind limbs for leaping; semiaquatic and terrestrial species.

Bell toad and toad frog are semantically related. Sometimes you can replace phrase "Bell toad" with "Toad frog", this phrases are similar.