selachoidei

from The Century Dictionary.

• noun In Günther's classification, the first suborder of plagiostomous fishes, contrasting with the Batoidei; the sharks, in a broad sense, or Squali, as distinguished from the rays. It has been divided by Haswell into the Palæoselachii and the Neoselachii.

from the GNU version of the Collaborative International Dictionary of English.

• noun plural (Zoöl.) Same as selachii.