GLOSSARY. 



Abdomen (Lat. abdo, I conceal ; or contracted from adipovien, derived from 



adeps, fat). The hinder portion of the body-cavity of the higher animals, 



containing the principal digestive and excretory organs. 

 Aberrant (Lat. aberro, I -wander away). Departing from the regular type. 

 Abnormal (Lat. ab, from ; norma, a rule). Irregular ; deviating from the 



ordinary standard. 

 Abomasdm. The fourth cavity of the complex stomach of the Euminaiits. 

 Abranchiate (Gr. a, without; bragchia, gills). Destitute of hrancliise or 



gills. 

 Acanthocephala (Gr. ahantha, a thorn ; kephaU, head). A class of parasitic 



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 p.articles from 



the outside. 

 Acephalous (Gr. li, without ; kcphaU, head). Not possessing a distinct hfad. 

 Actinosoma (Gr. aktin, a ray; scmia, body). Employed to designate the 



entire body of any Actinozoon, whether this be simple (as in the Sea-anem- 

 ones), or composed of several zooids (as in most Corals). 

 ACTINOZOA (Gr. aktin, a ray ; xoon, an animal). That division of the Ccden- 



terata of which the Sea-anemones may be taken as the type. 

 Adductor (Lat. adduco, I bring together). The muscles which bring to- 



getlier the valves of the shell of the Bivalve Molluscs are known as the 



"adductors." 

 Aerial (Gr. aer, 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 Echinoidea, through which are protruded 



the locomotive tube-feet. 

 Ametabolic (Gr. a, without ; yneta^oU, change). Applied to those insects 



which do not possess wings when fully grown, and which do not, therefore, 



pass through any well-marked metamorphosis. 

 Am(EBA (Gr. amoibos, changing). A species of Ehizopod, so called from the 



numerous changes of form which it undergoes. 

 Amorphous (Gr. a, without ; morplii, shape). Not having any definite figure. 

 Amphibia (Gr. am/phi, both ; bios, life). A class oF the Vertebrata comprising 



Frogs, Newts, and the like, which have always gills when young, but always 



develop lungs when fully growH. Most of them, therefore, live indifferently 



on land or in water. 

 Amphiocelous (Gr. amphi, at both ends ; koilos, hollow). Applied to vertebrae 



which are doubly concave, or hollow at both ends. 



