GLOSSARY. 



ABDOMEN (Lat. abdomen; from abdo, I conceal. Sometimes regarded as a 

 contraction of adipomen, from adeps, fat. ) The posterior cavity of the 

 body, containing the intestines and others of the viscera. 



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



ABIOGENESIS (Gr. a, without ; bios, life ; genesis, origin). Spontaneous gene- 

 ration, or the production of living beings without pre-existent life. 



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

 ordinary standard. 



ABOMASUM. The fourth cavity of the complex stomach of the Ruminants. 



ABRANCHIATE (Gr. a, without ; bragchia, gills). Destitiite of gills or bran- 

 chiae. 



ACALEPH.E (Gr. akalepM, a nettle). Applied formerly to the Jelly-fishes or 

 Sea-nettles, and other Radiate animals, in consequence 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. 



ACANTHOPTERYGII (Gr. akantha, spine; pterux, wing). A group of bony 

 fishes with spinous rays in the front part of the dorsal tin. 



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

 Cheese-mite is the type. 



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

 head. 



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

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



ACETABULUM. The cup-shaped socket of the hip-joint in Vertebrata. 



ACONTIA (Gr. akontion, a javelin). Long filaments, charged with thread-cells, 

 attached to the free edges of the mesenteries of Sea-anemones. 



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 ctenophores, or 

 comb-like rows of cilia. 



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

 body of any Actinozotin, whether this be simple (as in the Sea-anemones), 

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



ACTINOTROCHA (Gr. aktin, ray ; trochos, wheel). The form of Invertebrate 

 larva seen in some of the Annelides, &c., in which there is a circlet of cilia 

 round the anterior extremity. 



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

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



