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GLOSSARY. 



ALVEOLI (Lat. dim. of alvus, belly). Applied to the sockets of the teeth. 

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



or "avenues" 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 which do not, therefore, pass 



through any marked metamorphosis. 

 AMNION (Gr. amnos, a lamb). One of the fcetal membranes of the higher 



Vertebrates. 

 AMNIOTA. The group of Vertebrata in which the foetus is furnished with an 



amnion, comprising the Keptiles, Birds, and Mammals. 

 AM<EBA (Gr. amoibos, changing). A species of Khizopod, so called from the 



numerous changes of form which it undergoes. 

 AMCEBIF^RM. Kesembling an Amoeba in form. 

 AMORPHOZOA (Gr. a, without ; morphe, shape ; zoon, animal). A name 



sometimes used to designate the Sponges. 

 AMPHIBIA (Gr. amphi, both ; bios, life). The Frogs, Newts, and the like. 



which have gills when young, but can always breathe air directly when 



adult. 



AMPHKXELOUS (Gr. amphi, at both ends ; koilos, hollow). Applied to verte- 

 brae which are concave at both ends. 

 AMPHIDISCS (Gr. amphi, at both ends ; diskos, a quoit, or round plate). The 



spicula which surround the gemmules of Spongilla, and resemble two 



toothed wheels united by an axle. 

 AMPHIOXUS (Gr. amphi, at both ends ; oxus, sharp). The Lancelet, a little 



fish, which alone constitutes the order Pharyngobranchii. 

 AMPHIPNEUSTA (Gr. amphi, both ; pneo, I breathe). Applied to the "perenni- 



branchiate " Amphibians which retain their gills through life. 

 AMPHIPODA (Gr. amphi ; smdpous, a foot). An order of Crustacea. 

 ANAL (Lat. anus, the vent). Connected with the anus, or situated near the 



anus. 



ANALLANTOIDEA. The group of Vertebrata in which the embryo is not fur- 

 nished with an allantois. 



ANALOGOUS. Applied to parts which perform the same function. 

 ANAMNIOTA. The group of Vertebrata in which the embryo is destitute of 



an amnion. 

 ANARTHROPODA (Gr. a, without ; arthros, a joint ; pous, foot). That division 



of Annulose animals in which there are no articulated appendages. 

 ANCHYLOSIS or ANKYLOSIS (Gr. ankulos, crooked). The union of two bones 



by osseous matter, so that they become one bone, or are immovably joined 



together. 



ANDROGYNOUS (Gr. aner, a man ; gune, a woman). Synonymous with her- 

 maphrodite, and implying that the two sexes are united in the same in- 

 dividual. 

 ANDROPHORES (Gr. aner, a man ; and phero, I carry). Applied to medusiform 



gonophores of the Hydrozoa, which carry the spermatozoa, and differ in 



form from those in which the ova are developed. 

 ANNELIDA (a Gallicised form of Annulata). The Kinged Worms, which 



form one of the divisions of the Anarthropoda. 

 ANNULATED. Composed of a succession of rings. 



ANNULOIDA (Lat. annulus, a ring ; Gr. eidos, form). The sub-kingdom com- 

 prising the Echinodermata and the Scolecida ( = Echinozoa). 

 ANNULOSA (Lat. annulus). The sub-kingdom comprising the Anarthropoda 



and the Arthropoda or Articulata, in all of which the body is more or less 



evidently composed of a succession of rings. 

 ANOMODONTIA (Gr. anomos, irregular; odous, tooth). An extinct order of 



Keptiles, often called Dicynodontia. 

 ANOMURA (Gr. anomos, irregular ; oura, tail). A tribe of Decapod Crustacea, 



of which the Hermit -crab is the type. 



