GLOSSARY. © 357 
HaLLux (Lat. allex, the thumb or great toe). The innermost of the 
five digits which normally compose the hind foot of a Vertebrate 
animal. The great toe of man. 
Hxcrocotyius (Gr. hekaton, a hundred; kotulos, a cup). One of the 
“arms” of the male Cuttle-fishes, metamorphosed for reproductive 
purposes. 
HeEMELYTRA (Gr. hemi, half ; elutron, a sheath). The wing of certain In- 
sects (Hemiptera), in which the inner portion of the wing is hardened 
by chitine, and resembles the elytron of a beetle. 
HEMIMETABOLIO (Gr. hemi, half; metabole, change). Applied to those In- 
sects which undergo an incomplete metamorphosis. 
HEMIPTERA (Gr. hemi, half ; pteron, wing). An order of insects so called 
because the anterior wings are sometimes in the form of ‘‘ hemelytra.” 
HERMAPHRODITE (Gr. Hermes, Mercury ; Aphrodite, Venus). Possessing 
the organs of both sexes combined. 
HETEROCERCAL (Gr. heteros, diverse ; kerkos, tail). Applied to the tail 
of fishes when it is unequally lobed.’ ; 
Set aay (Gr. heteros, diverse ; genos, kind). Unlike or dissimilar 
in kind. 
HETEROMORPHIO (Gr. heteros, diverse; morphe, shape). Differing in form 
or shape. 
HTEROPODA (Gr. heteros, diverse ; podes, feet). An order of Gasteropo- 
dous Molluses. 
Hitum (Lat. hilum, a little thing). A small aperture or depression. 
HIRUDINEA\(Lat. hirudo, a horse-leech). The order of Annelida compris- 
' ing the leeches. 
HOLocEPHALI (Gr. holos, whole ; kephale, head). A sub-order of the Zlas- 
mobranchit. 
HOLOMETABOLIC (Gr. holos, whole ; metabole, change). Applied to those 
insects which undergo a complete metamorphosis. 
HOLOTHUROIDEA (Gr. holothowrion). The order of Echinodermata, com- 
prising the sea-cucumbers. 
Homocercat (Gr. homos, same; kerkos, tail). Applied to the tail of fishes 
when the two lobes are equal. 
HOMOGENEOUS (Gr. homos, same; genos, kind). Of like kind or nature. 
Homouogous (Gr. homos, same ; logos, a discourse). Applied to parts 
which are constructed upon the same fundamental plan. . 
HoMoMORFHOUS (Gr. homos, same; morphe, form). Having a similar 
external appearance or form. 
Humerus. The bone of the upper arm in Vertebrata. 
Hypatips (Gr. hudatis, a vesicle). The bladder-worm of the tape-worm 
of the dog. 
Hypra (Gr. hudra, a water-serpent). The generic name of the fresh- 
water polypes. 
Hyproipa (Gr. hudra » and eidos, form). The sub-class of the Hydrozoa, 
containing the animals most nearly allied to the Hydra. Often spoken 
of as the Hydroid Zoophytes. 
Hyproruiza (Gr. hudra ,; and rhiza, root), The adherent base or proxi- 
mal extremity of any Hydrozo6n. ; 
Hyprosoma (Gr. hudra,; and soma, body). The entire organism of any 
Hydrozoon. = : 
AlyprorHEca (Gr. hudra,; theke, a case). The little chitinous cups in 
which the polypites of the Sertularida and Campanularida are protected. 
Hyprozoa (Gr. hudra; zoén, animal). The class of the Celenterata, 
which comprises animals constructed after the type of the Hydra. 
HYMENOPTERA (Gr. humen, a membrane; pteron, a wing). An order of 
insects (comprising Bees, Ants, &c.), with four membranous wings, 
