> opisthocoelous- convex-concave "posterior hollow" (_( > procoelous- concave-convex "forward hollow" )_) > amphicoelous- concave-concave "both hollow" )_( > amphiplatyan- flat-flat "both flat" |_| > platycoelous- flat-concave "flat hollow" |_( > > 'acoelous'- "no hollow" ?- (_) What would be the translation of "flat convex" or has no such vertebral condition been found? Sam