_, a spindle). An extinct genus of
_Foraminifera_.

GANOID (Gr, _ganos_, splendour, brightness). Applied to those
scales or plates which are composed of an inferior layer of true
bone covered by a superior layer of polished enamel.

GANOIDEI. An order of Fishes.

GASTEROPODA (Gr. _gaster_, stomach; _pous_, foot). The class
of the Mollusca comprising the ordinary Univalves, in which
locomotion is usually effected by a muscular expansion of the
under surface of the body (the "foot").

GLOBIGERINA (Lat. _globus_, a globe; _gero_, I carry). A genus
of _Foraminifera_.

GLYPTODON (Gr. _glupho_, I engrave; _odous_, tooth). An extinct
genus of Armadillos, so named in allusion to the fluted teeth.

GONIATITES (Gr. _gonia_, angle). A genus of Tetrabranchiate
Cephalopods.

GRALLATORES (Lat. _gralloe_, stilts). The order of the long-legged
Wading Birds.

GRAPTOLITIDAE. (Gr. _grapho_, I write; _lithos_, stone). An extinct
sub-class of the _Hydrozoa_.

GYMNOSPERMS (Gr. _gumnos_, naked; _sperma_, seed). The Conifers
and Cycads, in which the seed is not protected within a seed-vessel.

HALITHERIUM (Gr. _hals_, sea; _therion_, beast). An extinct genus
of Sea-cows (_Sirenia_).

HAMITES (Lat. _hamus_, a hook). A genus of the _Ammonitidoe_.

HELIOPHYLLUM (Gr. _helios_, the sun; _phullon_, leaf). A genus
of Rugose Corals.

HELLADOTHERIUM (Gr. _Hellas_, Greece; _therion_, beast). An extinct
genus of Ungulate Mammals.

HEMIPTERA (Gr. _hemi_, and _pteron_, wing). An order of Insects
in which the anterior wings are sometimes "hemelytra."

HESPERORNIS (Gr. _Hesperos_, the evening star; _ornis_, bird).
An extinct genus of Birds.

HETEROCERCAL (Gr. _heteros_, diverse; _kerkos_, tail). Applied
to the tail of Fishes when it is unsymmetrical, or composed of
two unequal lobes.

HETEROPODA (Gr. _heteros_, diverse; _podes_, feet). An aberrant
group of the Gasteropods, in which the foot is modified so as
to form a swimming organ.

HIPPARION (Gr. _hipparion_, a little horse). An extinct genus
of _Equidoe_.

HIPPOPOTAMUS (Gr. _hippos_, horse; _potamos_, river). A genus
of Hoofed Quadrupeds--the "River-horses."

HIPPURITIDAE. (Gr. _hippos_, horse; _oura_, tail). An extinct family
of Bivalve Molluscs.

HOLOPTYCHIUS (Gr. _holos_, whole; _ptuce_, wrinkle). An extinct
genus of Ganoid Fishes.

HOLOSTOMATA (Gr. _holos_, whole; _stoma_, mouth). A division
of _Gasteropodous Molluscs_, in which the aperture of the shell
is round