GLOSSARY. 289 



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. 



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



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

 ordinary standard. 



ABRANCHIATE (G-r. a, without ; bragchia, gills). Destitute of gills or 

 branchiae. 



ACALEPHJS (G-r. akalephe, a nettle). Applied formerly to the Jelly-fishes or 

 Sea-nettles, and other Radiate animals, in conseqiience of their power of 

 stinging, derived from the presence of microscopic cells, called ' thread- 

 cells,' in the integument. 



ACANTHOCEPHALA (Gr. akantha, a thorn ; kephale, head). A class of para- 

 sitic worms, in which the head is armed with spines. 



ACANTHOMETRINA (Gr. akantha ; and metra, the womb). A family of Pro- 

 tozoa, characterised by having radiating siliceous spines. 



ACARINA (Gr. akari, a mite). A division of the Arachnida, of which the 

 Cheese-mite is the type. 



ACEPHALOUS (Gr. a, without ; kephale, the head). Not possessing a distinct 

 head. 



ACETABULA (Lat. ocetabulum, a cup). The suckers with which the cephalic 

 processes of many Cephalopoda (Cuttle-fishes) are provided. 



ACRITA (Gr. akritos, confused). A term sometimes employed as synonymous 

 with Protozoa, or the lowest division of the animal kingdom. 



ACTINOMERES (Gr. aktin, a ray ; meros, a part). The lobes which are 

 mapped out on the surface of the body of the Ctenophora, by the cteno- 

 phores, or comb-like rows of cilia. 



ACTINOSOMA (Gr. aktin; and soma, body). Employed to designate the 

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

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



ACTINOZOA (Gr. aktin ; and zoon, an animal). That division of the C&l- 

 enterata, of which the Sea- Anemones may be taken as the type. 



ADELARTHROSOMATA (Gr. adelos, hidden ; arthros, joint ; soma, body). An 

 order of the Arachnida. 



AGAMIC (Gr. a, without; gamos, marriage). Applied to all forms of repro- 

 duction in which the sexes are not directly concerned. 



AMBULACRA (Lat. ambulacrum, a place for walking). The perforated spaces 

 through which are protruded the tube-feet, by means of which locomotion 

 is effected in the Echinodermata. 



AMBULATORY (Lat. ambulo, I walk). Formed for walking. Applied to a 

 single limb, or to an entire animal. 



AMETABOLIC (Gr. a, without; metabole, change). Applied to those insects 

 which do not possess wings when perfect, and do not, therefore, pass 

 through any marked metamorphosis. 



AMOSBA (Gr. amoibos, changing). A species of Rhizopod, so called from 

 the numerous changes of form which it undergoes. 



YOL. I. U 



