667 



GLOSSARY 



OF ANA.T03£ICAL AND OTHER SCIENTIFIC TERMS USED IN THESE 



LECTURES. 



Abdomen. (Lat. abda, 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 firom the attachment 



of the ventral fins to the abdomen behind the pectorals. 

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



which deviate most from the type of their natural group. 

 Abranchiate. (Gr. o, without ; bragchia, gillsw) When an animal is devoid of 



gills. 

 AcALEPHA. (Gr. akalepke, 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. akatitkos, a spine ; kephale, a head.) The order of intes • 



tinal worms ha^-ing 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. 

 AcARiDJE. The family of which the genus Acarus is the type. 

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

 sitic upon sponges. 

 AcEPHALOtrs. (Gr. a, without ; Acp^/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. 

 AcErABUEA. (Lat acetabulnm, a shallow cup.) The fleshy sucking-cups with 



which 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 berries to a slender stem. 

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

 AcRiTA, (Gr. akritos, 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 horni 



or feelers. 

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

 AxBUMiNiPAROus A part, gland, or surface which secretes albumen. 

 AxBusoNOUs. (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 ; so that the successive series of in- 



