GLOSSARY, 
ABDOMEN (Lat. abdo, I conceal). The posterior cavity of the body, con- 
taining the intestines and others of the viscera. In many Invertebrates 
there is no separation of the body-cavity into thorax and abdomen, and 
it is only in the higher Annulosa that a distinct abdomen can be said to 
exist. 
grteas (Lat. abervo, I wander away). Departing from the regular 
ype. 
ABNORMAL (Lat. ab, from; norma, a rule). Irregular; deviating from 
the ordinary standard. 
ABoMASUM. The fourth cavity of the complex stomach of the Ruminants. 
ee aes (Gr. a, without; bragchia, gills). Destitute of branchiz 
or gills. 
ACANTHOCEPHALA (Gr. acantha, a thorn; kephale, head). <A class of para- 
sitic worms in which the head is armed with spines. 
ACARINA (Gr. akari, a mite). A division of the Arachnida, comprising 
the mites and ticks. 
ACCRETION (Lat. accresco, I grow larger). The process by which inorganic 
bodies (such as crystals) grow larger, by the addition of fresh particles 
from the outside. 
ACEPHALOUS (Gr. a, without; kephale, head). Not possessing a distinct 
head. 
AcTINOSOMA (Gr. aktin, a ray ; soma, body). Employed to designate the 
entire body of any Actinozoén, whether this be simple (as in the sea- 
anemones) or composed of several zodids (as in most corals), 
AOTINOZOA (Gr. aktin, a ray ; zon, ananimal). That division of the Celen- 
terata of which the sea-anemones may be taken as the type. 
ADpDucToR (Lat. adduco, I bring together). The muscles which bring to- 
gether the valves of the shell of the Bivalve molluscs are known as the 
** adductors.”’ 
AERIAL (Gr. aér, air). Living in the air ; enjoying the power of flight. 
AMBULACRA (Lat. ambulacrum, a place for walking). The perforated 
spaces or ‘‘avenues” in the shell of the Hchinoidea, through which are 
protruded the locomotive tube-feet. 
AMETABOLIC (Gr. a, without ; metabole, change), Applied to those insects 
which do not possess wings when fully grown, and which do not, there- 
fore, pass through any well-marked metamorphosis. 
Ama@BA (Gr. amoibos, changing). A species of Rhizopod, so called from 
the numerous changes of form which it undergoes. 
AmorPHOUS (Gr. a, without; morphe, shape). Not having any definite 
figure. 
AMPHIBIA (Gr. amphi, both ; bios, life). <A class of the Vertebrata compris- 
ing Frogs, Newts, and the like, which have always gills when young, 
but always develop lungs when fully grown. Most of them, therefore, 
live indifferently on land or in water. 
AMPHICG@LOUS (Gr. amphi, at both ends ; koilos, hollow). Applied to ver- 
tebre which are doubly concave, or hollow at both ends. 
