GLOSSARY 



Abdomen. (Lat. abdo, I conceal.) In mammals, that portion of the 

 body-cavity which is separated from the thorax or chest by th? 

 diaphragm. In insects the third or last portion. 



Acalephae. (Gr. &caA.rj4>rj, a nettle.) Jelly-fishes or sea-nettles. 



Acanthocephala. (a/ccu/flo, a thorn ; Kf<aA.7/, head.) Parasitic worms 



Acarina. (Gr. &K*?I, a mite.) An order of Arachnida. 



Actinozoa. (Gr. averts, a ray ; favv, animal.) A class of Coelenterata. 



Acephalous. (Gr. a, without ; Ke<J>aA^, the head.) Destitute of a dis- 

 tinct head. 



Adductor. Referring to muscles in clams which draw the shells 

 together. 



Albumen. (Lat. albus, white.) Resembling the white of an egg. 



Alveolus. A hollow cavity forming a socket for the teeth. 



Ambulacrum. (Lat. from ambulare, to walk, a garden-walk.) The 

 perforated spaces in the shell of Echinus. 



Ametabolic. (Gr. a, without ; /lerajSoA.^, change.) Referring to in- 

 sects and other animals which do not undergo a complete meta- 

 morphosis. 



Amoeba. (Gr. dp<K/94, a change.) One of the Rhizopods that is con- 

 tinually changing its shape. 



Amphibia. (Gr. ap/tyi, both ; /3tos, life.) A class of vertebrates, 

 breathing in water while young and in air when mature. The term 

 amphibious is applied to fishes, mollusks, etc., that are capable of 

 changing the nature of their respiration at will. 



Amphiccelous. (Gr. ofupj, both ; Kol\os, hollow.) Vertebne with a 

 cup at either end. 



Amphioxus. (Gr. a/jupl, both ; o|ts, sharp.) The Lancelot, which 

 tapers to either end of its body. 



Amphipoda. (Gr. d/t<J>/, both ; TTOVS, foot.) An order of Crustacea, 

 whose feet serve both for walking and swimming. 



