Is it farther or further?
invertebrate in·ver·te·brate (ĭn-vûr'tə-brĭt, -brāt')
Lacking a backbone or spinal column; not vertebrate.
Of or relating to invertebrates.
Adjective Having no backbone or spinal column.
Noun An animal that has no backbone or spinal column and therefore does not belong to the subphylum Vertebrata of the phylum Chordata. Most animals are invertebrates. Corals, insects, worms, jellyfish, starfish, and snails are invertebrates.