e). A genus of long-tailed Crustaceans from the
Coal-measures.

ANTLERS. Properly the branches of the horns of the Deer tribe
(_Cervidoe_), but generally applied to the entire horns.

APIOCRINIDAE (Gr. _apion_, a pear; _krinon_, lily). A family of
Crinoids--the "Pear-encrinites."

APTERYX (Gr. _a_, without; _pterux_, a wing). A wingless bird
of New Zealand, belong to the order _Cursores_.

AQUEOUS (Lat. _aqua_, water). Formed in or by water.

ARACHNIDA (Gr. _arachne_, a spider). A class of the _Articulata_,
comprising Spiders, Scorpions, and allied animals.

ARBORESCENT. Branched like a tree.

ARCHAEOCIDARIS (Gr. _archaios_, ancient; Lat. _cidaris_, a diadem).
A Palaeozoic genus of Sea-urchins, related to the existing _Cidaris_.

ARCHAEOCYATHUS (Gr. _archaios_, ancient; _kuathos_, cup). A genus
of Palaeozoic fossils allied to the Sponges.

ARCHAEOPTERYX (Gr. _archaios_, ancient; _pterux_, a wing). The
singular fossil bird which alone constitutes the order of the
_Saururoe_.

ARCTOCYON (Gr. _arctos_, bear; _kuon_, dog). An extinct genus
of Carnivora.

ARENACEOUS. Sandy, or composed of grains of sand.

ARENICOLITES (Lat. _arena_, sand; _colo_, I inhabit). A genus
founded on burrows supposed to be formed by worms resembling
the living Lobworms (_Arenicola_).

ARTICULATA (Lat. _articulus_, a joint). A division of the animal
kingdom, comprising Insects, Centipedes, Spiders, and Crustaceans,
characterised by the possession of jointed bodies or jointed
limbs. The term _Arthropoda_ is now more usually employed.

ARTIODACTYLA (Gr. _artios_, even; _daktulos_, a finger or toe).
A division of the hoofed quadrupeds (_Ungulata_) in which each
foot has an even number of toes (two or four).

ASAPHUS (Gr. _Asaphes_, obscure). A genus of Trilobites.

ASCOCERAS (Gr. _askos_, a leather bottle; _keras_, horn). A genus
of Tetrabranchiate Cephalopods.

ASIPHONATE. Not possessing a respiratory tube or siphon. (Applied
to a division of the _Lamellibranchiate_ Molluscs.)

ASTEROID (Gr. _aster_, a star; and _eidos_, form). Star-shaped,
or possessing radiating lobes or rays like a star-fish.

ASTEROIDEA. An order of _Echinodermata_, comprising the Star-fishes,
characterised by their rayed form.

ASTEROPHYLLITES (Gr. _aster_, a star; _phullon_, leaf). A genus
of Palaeozoic plants, with leaves in whorls.

ASTRAEIDAE (Gr. _Astroea_, a proper name). The family of the
Star-corals.

ASTYLOSPONGIA (Gr. _a_, without; _stulos_