GLOSSARY. 351 



ARCTOCYON (Gr. arctos, beai ; kaon, dog). An extinct gemis of Carnivora. 



ARENACEOUS. Sandy, or composed of grains of sand. 



ARENICOLITES (Lat. arena, sand ; col<>, I inhabit). A genus founded on bur- 

 rows supposed to be formed by worms resembling the living Lobworms 

 (Arenicola). 



ARTICULATA (Lat. articulus, a joint). A division of the animal kingdom, coin- 

 prising Insects, Centipedes, Spiders, and Crustaceans, characterised by the 

 possession of .jointed bodies or jointed limbs. The term Arthropods is now 

 more usually employed. 



ARTIODACTYLA (Gr. artios, even ; daktulos, a finger or toe). A division of the 

 hoofed quadrupeds (Uiujulata) in which each foot has an even number of 

 toes (two or four). 



ASAPHUS (Gr. asaphes, obscure). A genus of TrilobiteB. 



ASCOCERAS (Gr. askos, a leather bottle ; keras, horn). A genus of Tetrabran- 

 chiate Cephalopods. 



ASIPHONATE. Not possessing a respiratory tube or siphon. (Applied to a 

 division of the Lamellibrancli ic/.te Molluscs.) 



ASTKKOID (Gr. aster, a star; and eidos, form). Star-shaped, or possessing 

 radiating lobes or rays like a star-fish. 



ASTEROIDEA. An order of Kchiiwdermata, comprising the Star-fishes, charac- 

 terised by their rayed form. 



ASTEROPHYLLITES (Gr. aster, a star ; phullon, leaf). A genus of Palaeozoic 



plants, with leaves in whorls. 



ASTR^ID^E (Gr. Astrcea, a proper name). The family of the Star-corals. 



ASTYLOSPOXGIA (Gr. a, without ; stulos, a column ; spoggos, a sponge). A 

 genus of Silurian Sponges. 



ATHYRIS (Gr. a, without ; thura, door). A genus of Brachiopods. 



ATRYPA (Gr. a, without ; trupa, a hole). A genus of Brachiopods. 



AYES (Lat. avis, a bird). The class of the Birds. 



AVICULA (Lat. a little bird). The genus of Bivalve Molluscs comprising the 

 Pearl-oysters. 



AXOPHYLLUM (Gr. axon, a pivot; phullon, a leaf). A genus of Rugose 

 Corals. 



Azoic (Gr. a, without ; zoe, life). Destitute of traces of living beings. 



BACULITES (Lat. baculum, a staff). A genus of the Ammonitidce. 



BAL,ENA (Lat. a whale). The genus of the Whalebone Whales. 



BALANiDvE (Gr. balanos, an acorn). A family of sessile Cirripedes, commonly 

 called " Acorn-shells." 



BATRACHIA (Gr. batrachos, a frog). Often loosely applied to any of the Am- 

 phibia, but sometimes restricted to the Amphibians as a class, or to the 

 single order of the A noura. 



BELEMNITID^E (Gr. belemnon, a dart). An extinct group of Dibranchiate Ceph- 

 alopods, comprising the Belemnites and their allies. 



BELEMNOTEUTHIS (Gr. belemnon, a dart ; leuthis, a cuttle-fish). A genus allied 

 to the Belemnites proper. 



BELINURUS (Gr. belos, a dart ; oura, tail). A genus of fossil King-crabs. 



BEU.EROPHON (Gr. proper name). A genus of oceanic Univalves (Heteropoda). 



BKLOTEUTHIS (Gr. belos, a dart ; teuthis, a cuttle-fish). An extinct genus of 

 Dibranchiate Cephalopods. 



BEYRICHIA (named after Prof. Beyrich). A genus of Ostracode Crustaceans. 



BILATERAL. Having two symmetrical sides. 



BIMANA (Lat. bis, twice ; manus, a hand). The order of Mammalia compris- 

 ing man alone. 



BIPEDAL (Lat. bis, twice; pes, foot). Walking upon two legs. 



BIVALVE (Lat. bis, twice ; valvie, folding-doors). Composed of two plates or 

 valves ; applied to the shell of the iMmellibranchiata and Brack iopoda, and 

 to the carapace of certain Crustacea. 



BLASTOIDEA (Gr. blastos, a bud ; and eidos, form). An extinct order of Kcld- 

 nodermata, often called Pentremites. 



BRACHIOPODA (Gr, brwhion, an arm ; pous, the foot), A class of the 



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