264 GLOSSARY. 



Anapophyses. Processes of the lumbar vertebras. 



Anchylosis. The union of two bones to form one bone. 



Androgeny = hermaphroditism. 



Androphores. The gonophores carrying the male elements in 

 the Hydroida. 



Anenterous. Without intestines. 



Antenna. Two or four movable jointed organs situated before 

 or between the eyes in the Arthropoda. Also in some worms, 

 but unjointed. 



AntennulcB. The smaller antennae when four are present. 



Anthogenesis. " That mode of reproduction in which there inter- 

 venes a form furnishing male and female pupa? from which 

 the sexual individuals issue." It occurs in some of the Phy- 

 tophthiria. 



Antigeny. Sexual dimorphism. 



Antimeres. "Equivalent parts or homotypes" (Gegeribauer}. 

 The parts formed by the segmentation of the embryo. " They 

 vary in number ; each segment of a bilaterally symmetrical 

 animal (Vertebrate or Arthropod) has two : " there are as many 

 as eight in the Ctenophora. " The increase of a function may be 

 provided for by a multiplication of organs;" "hence the next 

 step in complexity is the formation of a chain of similar groups 

 in succession." To each element in this chain is given the 

 name of metamere. Thus "a vertebrate animal is made up of 

 a series of successive externally-unjointed metameres, each con- 

 sisting of two symmetrical antimeres " (Macalister, An .Morph. ) . 



Antlia. The suctorial mouth-organ of the Lepidoptera. 



Anus. The termination of the intestine. 



Aorta. The artery arising from the left ventricle of the heart. 



Apodemata. Certain processes in the interior of the thorax of 

 the higher Crustacea, serving for the attachment of muscles. 



Aponeurosis. The expanded tendon of a muscle. 



Apophysis. A process of a bone ("a mischievous word," Parker). 



Aproctous. Without an anal opening. 



Apteria. The naked parts in the skin of birds where feathers do 

 not occur. 



Aptychi. " Plates of a shelly substance " found associated with 

 ammonites, or sometimes lodged within the shell. 



Arachnidium. The spinning-apparatus of the spiders. 



Archceostomatotts. When the mouth of the gastrula is retained, 



