667 



GLOSSARY 



OF ANATOMICAL AND OTHER SCIENTIFIC TERMS USED IN THESE 



LECTURES. 



Abdomeis. (Lat. ahdo, I conceal.) The posterior and principal cavity containing 



the bowels and many other viscera of the animal. The abdomen is distinct from 



the thorax in crustaceans, spiders, and insects. 

 Abdominales. (Lat. abdomen.) An order of fishes, so called from the attachment 



of the ventral fins to the abdomen behind the pectorals. 

 Aberrant. (Lat. aberro, I wander from.) This term is applied to those species 



Avhich deviate most from the type of their natural group. 

 Abranchiate. (Gr. cr, without ; bragchia, gills.) When an animal is devoid of 



gills. 

 AcALEPHA. (Gr. akalephe, a nettle.) The class of radiated animals with soft 



skins, which have the property of stinging like a nettle. 

 AcALEPHOiD. Like a Medusa or other common form of Acalepha. 

 AcANTHocEPHALA. (Gr. akanthos, a spine ; kephale, a head.) The order of intes • 



tinal worms having the head armed with spines or hooks. 

 AcARUs. (Gr. akari, a mite.) The name of a genus of Arachnida, to which the 



cheese-mite and allied species belong. 

 AcARiD^. The family of which the genus Acarns is the type. 

 AcASTA. (Gr. akaste.) A name arbitrarily applied to a genus of Barnacles, jiara- 



sitic upon sponges. 

 Acephalous. (Gr. a, without ; ^ej9/w?e, head.) Headless. The animals in which 



a distinct head is never developed. 

 AcEPHALOCTST. The parasitic hydatid, which consists of a cyst or bag without a 



head. 

 AcErABiJLA. (Lat acetabulum, a shallow cup.) The fleshy sucking-cups with 



Avhich many of the invertebrate animals are provided. 

 Acini. (Lat. acinum, a berry.) The secerning parts of glands, when they are 



suspended like grains or small beiTies to a slender stem. 

 Acoustic. (Gr, akouo, I hear.) Appertaining to sound, or the organ of hearing. 

 AcRiTA. (Gr. akrifos, confused.) A term applied to the lowest animals, in which 



the organs, and especially the nervous system, were supposed to be confusedly 



blended with the other tissues. 

 Actinia. (Gr. aktin, a ray.) The genus of Polypes, which have many arms 



radiating from around the mouth. 

 Actinoceros. (Gr. aktin, a ray ; keras, a horn.) A generic term, signifying the 



radiated disposition of parts like horns. 

 Adipose. (Lat. adeps, fat.) Fatty. 

 Akera. (Gr. a, without ; keras, a horn.) The family of Mollusca, without horns 



or feelers. 

 Alar. (Lat. ala, a wing.) Belonging to a wing. 

 Albuminiparous. a part, gland, or surface which secretes albumen. 

 Albuminous. (Lat. albumen, white of egg.) Consisting of albumen, or the sub- 

 stance which forms the white of an egg. 

 Aliform. Shaped like a wing. 

 Alternate generation. That modification of generation in which the young do 



not resemble the parent, but the grand-parent j so that the successive series of in- 



