394 GLOSSARY 



AMBONYCHIA (Gr. ambon, a boss; onux, claw). A genus of 

 Palaeozoic Bivalves. 



AMBULACRA (Lat. ambulacrum, a place for walking). The per- 

 forated spaces or " avenues " through which are protruded the 

 tube-feet, by means of which locomotion is effected in the 

 Echinodermata. 



AMMONiTiDyE. 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-Am- 

 mon. 



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

 name sometimes used to designate the Sponges. 



AMPHIBIA (Gr. amphl, both; bios, life). The Frogs, Newts, 

 and the like, which have gills when young, but can always 

 breathe air directly when adult. 



AMPHICYON (Gr. am phi, both implying doubt; kuDn, dog). An 

 extinct genus of Carnivora. 



AMPHILESTES (Gr. amphl, both; lestZs, a thief). A genus of 

 Jurassic Mammals. 



AMPHISPONGIA (Gr. amphi, both; spoggos, sponge). A genus 

 of Silurian sponges. 



AMPHISTEGINA (Gr. dmphi, both; stege', roof). A genus of 

 Foraminifera. 



AMPHITHERIUM (Gr. amphi, both; therion, beast). A genus of 

 Jurassic Mammals. 



AMPHITRAGULUS (Gr. amphi, both; dim. of tragos, goat). An 

 extinct genus related to the living Musk-deer. 



AMPLEXUS (Lat. an embrace). A genus of Rugose Corals. 



AMPYX (Gr. ampux, a wreath or wheel). A genus of Trilo- 

 bites. 



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

 That division of Annulose animals in which there are no 

 articulated appendages. 



ANCHITHERIUM (Gr. agchi, near; therion, beast). An extinct 

 genus of Mammals. 



ANCYLOCERAS (Gr. agkulos, crooked; ceras, horn). A genus of 

 Ammonitidce. 



ANCYLOTHERIUM (Gr. agkulos, crooked; therion, beast). An 

 extinct genus of Edentate Mammals. 



ANDRIAS (Gr. andrias, image of man). An extinct genus of 

 tailed Amphibians. 



ANGIOSPERMS (Gr. angeion, a vessel; sperma, seed). Plants 

 which have their seeds enclosed in a seed-vessel. 



ANNELIDA (a Gallicised form of Annulata}. The Ringed 

 Worms, which form one of the divisions of the Anarthropoda. 



ANNULARIA (Lat. annulus, a ring). A genus of Palaeozoic 

 plants, with leaves in whorls. 



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 suc- 

 cession of rings. 



ANOMODONTIA (Gr. anomos, irregular; odous, tooth). An ex- 

 tinct order of Reptiles, often called Dicynodontia. 



