acanthodei

from The Century Dictionary.

• In Agassiz's classification, an order of selachians or sharks having the endoskeleton and parts of the skull calcified; pterygoquadrate articulated with the cranium and sometimes bearing teeth; fins, except the caudal, with stout anterior spines; and shagreen scales quadrate and compactly arranged.
• The name originally given by Agassiz to the family Acanthodidæ (which see).