GLOSSARY. 381 



ARCTOCYON (Gr. arctos, beai ; kuon, dog). An extinct genus of Carnivora. 



ARENACEOUS. Sandy, or composed of grains of sand. 



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



rows supposed to be funned by worms resembling the living Lobworms 



(Arenicola). 



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

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

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



more usually employed. 

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



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



toea (two or four). 



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

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



chiate Cephalopods. 

 ASIPHONATE. Not possessing a respiratory tul>e or siphon. (Applied to a 



division of the Lamellibrancl< io.te Molluscs.) 

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



radiating lobes or rays like a star-fish. 

 ASTI;ROIDEA. 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. 



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

 ASTYLOSPOSGIA (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. , without; zoe, life). Destitute of traces of living beings. 



BACULITES (Lat. laculum, a staff). A genus of the Ammo nit idee. 



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



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



called " Acorn-shells." 

 BATRACHIA (Gr. latrachos, 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 Anoura. 

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



alopods, comprising the Belemnites and their allies. 

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



to the Belemnites proper. 



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

 BELLEROPHON (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 ; valvte, folding-doors). Composed of two plates or 



valves ; applied to the shell of the Lamellibranchiata and Erach',o L wda, and 



to the carapace of certain Crustacea. 

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



nodcrmata, often called Pentremites. 

 BRACHIOPODA (Gr, b-achion, an arm ; pous, the foot). A class of the Mollut- 



