12 GLOSSARY. 



ArthrS'logy (Gr. arthron, a joint ; logos, a discourse). The 



branch of Anatomy which treats of the joints. 

 Arthro'poda (Gr. art/iron, a joint; pous, podos, a foot). A 



division of the Invertebrata which comprises all those 



animals which have jointed appendages. 

 Arthrozo'ic (Gr. arthron, a joint ; zoon, an animal). A series 



of the Invertebrata which embraces the Arthropoda, 



Nematoscolices, and Chaetognatha. 

 Articnla're (L. relating to a joint). A bone of the lower jaw, 



which, in most of the Vertebrata but mammals, results 



from one of the ossifications of Meckel's cartilage. 

 Articula'ta (L. articulus, a joint). A group of Brachiopods in 



which the two valves of the shell are united by a hinge. 

 Arti'culi (L. joints). The joints of the cirri of the Crinoidea. 

 Artiodac'tyla (Gr. artios, even; daktulos, a finger or toe). A 



group of the Ungulata, the members of which have an 



even number of digits. 



Aryepiglot'tic ligaments. Folds of mucous membrane extend- 

 ing from the arytenoid cartilages to the epiglottis. 

 Aryte'noid (Gr. arytaina, a pitcher or ladle ; eidos, shape). 



The name of the two pyramidal cartilages of the larynx 



which are situated on the posterior border of the cricoid 



cartilage. 

 Arytenoi'deus. The muscle which passes from one arytenoid 



cartilage to the other. 



Ascala'bota (Gr. askalabos, a newt). A group of the Lacertilia. 

 As'ci (Gr. askos, a leathern bottle). The name given to the 



sporangia of fungi, in which spores are produced by 



division of the protoplasm. 

 Ascidia'rium (Gr. askos, a bag or leathern bottle ; cidos, form). 



The structure which is formed by the ascidiozooids in the 



development of an Ascidian. 

 Ascidioi'da (Gr. askos, a bag ; eidos, form). A group of Mol- 



lusca, so called because they resemble in shape a two- 

 . necked bottle. 

 Asci'tes (Gr. askos, a bottle). Dropsy of the abdomen ; so 



called from the bottle-like appearance to which it gives rise. 

 Asco'nes (Gr. askon, a skin). A family of the Calcisponga. 

 As'cospores (Gr. askos, a leathern bottle ; spora, a seed). Spores 



produced by division of protoplasmic masses, as in Torula, 



Afucor, &c. 

 Asex'uaL Not sexual ; applied to modes of reproduction in 



which sex takes no share, as gemmation, fission, &c. 



