raemaxillae anchylose with the maxillae, so as
to be irrecognisable in the adult.

INVERTEBRATA (Lat. _in_, without; _vertebra_, a bone of the back).
Animals without a spinal column or backbone.

ISOPODA. (Gr. _isos_, equal; _podes_, feet). An order of _Crustacea_
in which the feet are like one another and equal.

KAINOZOIC (Gr. _kainos_, recent; _zoe_, life). The Tertiary period
in Geology comprising those formations in which the organic remains
approximate more or less closely to the existing fauna and flora.

LABYRINTHODONTIA (Gr. _laburinthos_, a labyrinth; _odous_, tooth).
An extinct order of _Amphibia_, so called from the complex
microscopic structure of the teeth.

LACERTILIA (Lat. _lacerta_, a lizard). An order of _Reptilia_
comprising the Lizards and Slow-worms.

LAMELLIBRANCHIATA (Lat. _lamella_, a plate; Gr. _bragchia_, gill).
The class of _Mollusca_ comprising the ordinary bivalves,
characterised by the possession of lamellar gills.

LEPIDODENDRON (Gr. _lepis_, a scale; _dendron_, a tree). A genus
of extinct plants, so named from the scale-like scars upon the
stem left by the falling off of the leaves.

LEPIDOPTERA (Gr. _lepis_, a scale; _pteron_, a wing). An order
of Insects, comprising Butterflies and Moths, characterised by
possessing four wings which are usually covered with minute scales.

LEPIDOSIREN (Gr. _lepis_, a scale; _seiren_, a siren--the generic
name of the Mud-eel or _Siren lacertina_). A genus of Dipnoous
fishes, comprising the "Mud-fishes."

LEPIDOSTROBUS (Gr. _lepis_, a scale; _strobilos_, a fir-cone).
A genus founded on the cones of _Lepidodendron_.

LEPTAENA (Gr. _leptos_. slender). A genus of Brachiopods.

LINGULA (Lat. _lingula_, a little tongue). A genus of Brachiopods.

LYCOPODIACEAE (Gr. _lupos_, a wolf; _pous_, foot). The group of
Cryptogamic plants generally known as "Club-mosses."

MACHAERACANTHUS (Gr. _machaira_, a sabre; _acantha_, thorn or spine).
An extinct genus of Fishes.

MACHAIRODUS (Gr. _machaira_, a sabre; _odous_, tooth). An extinct
genus of Carnivora.

MACROTHERIUM (Gr. _makros_, long; _therion_. beast). An extinct
genus of Edentata.

MACRURA (Gr. _makros_, long; _oura_, tail). A tribe of Decapod
_Crustaceans_ with long tails (e.g., the Lobster, Shrimp, &c.)

MAMMALIA (Lat. _mamma_, the breast). The class of Vertebrate animals
which suckle their young.

MANDIBLE (Lat. _mandibulum_, a jaw). The upper pair of jaws in
Insects; also applied t