GLOSSARY. 



Abdomen (Lat. abdo, I conceal). The posterior cavity of the body, contain- 

 ing the intestines and others of the viscera. In many Invertebrates there 

 is no separation of the body-cavity into thorax and abdomen, and it is only 

 in the higher Annulosa that a distinct abdomen can be said to exist. 



Aberrant (Lat. aherro, I wander away). Departing from the. regular type. 



Abnormal (Lat. ccb, from ; Twrnui, a rule). Irregular ; deviating from the 

 ordinary standard. 



AcRODUS (Gr. akros, high ; odous, tooth). A genus of the Cestraciont fishes, 

 so called from the elevated teeth. 



ACROGENS (Gr. akros, high ; gennao, I produce). Plants which increase in 

 height by additions made to the summit of the stem by the union of the 

 bases of the leaves. 



AcROTRETA (Gr. akros, high ; tretos, pierced). A genus of Brachiopods, so 

 called from the presence of a foramen at the summit of the shell. 



AcTiNOCRiNUS (Gr. aktin, a ray ; krinon, a lily). A genus of Crinoids. 



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

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



.^GLINA {jEgle, a sea-nymph). A genus of Trilobites. 



.^PiORNis (Gr. aipus, huge; ornis, bird). A genus of gigantic Cursorial 

 birds. 



Agnostus (Gr. a, not ; gignosko, I know). A genus of Trilobites. 



Alces (Lat. alces, elk). The Eiiropean Elk or Moose. 



Alecto (the proper name of one of the Furies). A genus of Polyzoa. 



Alethopteris (Gr. alethes, true ; pteris, fern). A genus of Ferns. 



Alg^ (Lat. alga, a marine plant). The order of plants comprising the Sea- 

 weeds and many fresh-water plants. 



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



AiiBLTPTERUS (Gr. amblus, blunt ; pteron, fin). An order of Ganoid Fishes, 



A3IB0NYCHIA (Gr. ambou, a boss ; onux, claw). A genus of Paleozoic Bi- 

 valves. 



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 efiected in the Echinodermata. 



Ammonitid^. a family of Tetrabranchiate Cephalopods, so called from the 

 resemblance of the shell of the type-genus, Ammonites, to the horns of the 

 Egyptian God, Jupiter-Ammon. 



Amorphozoa (Gr. a, without ; morphe, shape ; zoon, animal). A name some- 

 times used to designate the Sponges. 



Amphibia (Gr. a/raphi, both ; bios, life). The Frogs, Newts, and the like, 

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

 adult. 



Amphicyon (Gr. ampM, both — implying doubt; kuon, dog). An extinct 

 genus of Carnivora. • 



