GLOSSAUY. 363 



AuuiCLK (Lat. auricula, a little ear). Applieil to the cavity of the heart wliii'h 



drives the blood into the ventricle. 

 Avts (Lat. avis, a bird). Tlie class of the Birds. 



Balancers. The knobbed filaments which represent the posterior pair of wings 



in Dipterous Insects ; also called "poisers." 

 Balanid.^ (Gr. balanos, an acorn). A family of Cirripedia, commonly spoken 



of as "Acorn-shells." 

 Baleen (Lat. balmm, a whale). The horny plates wliich are placed in the 



upper surface of the mouth of the true or ** whalebone " Whales. 

 Batrachia (Gr. hatrachos, a frog). Generally applied loosely to any of the 



Amp/iibia, but sometimes used to designate either the entire class of the 



Amphibians, or the single order of the Anoura, 

 Bifid. Cleft into two parts ; forked. 

 BiMANA (Lat. bis, twice ; maniis, a hand). The order of Mammalia constituted 



by Man alone. 

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



valves ; applied to the shell of the LameUibranchiata and Brachiopoda, and 



to the carapace of certain Crustaceu. 

 Blastoidea (Gr. blastos, a bud ; eidos, form). An extinct order of Echinoder- 



mata, often called Pentremites. 

 Brachiopoda (Gr. brackion, the arm ; podes, feet). A class of the lower Mol- 



litsca, often called ' ' Lamp-shells, " characterised by having two fleshy ciliated " 



" arms " attached to the sides of the mouth. 

 Brachyura (Gr. brachus, short ; <mra, tail). A tribe of Decapod Crustaceans 



with short tails ; commonly known as Crabs. 

 BbaOT. Overlapping appendnges or plates which protect the polypites in many 



of the Oceanic Hydrozoa. 

 BUANCHIA (Gr. bragchia, the gill of a fish). A respiratory organ adapted for 



breathing air dissolved in water. 

 Branchiate. Possessing gills. 

 Bronchi (Gr. hrogchos, the windpipe). The branches of the windpipe (tracliea), 



by which the air is conveyed to the lungs. 

 BRUtv (Lat. brutiis, heavy, stupid). Sometimes used to designate the Mam- 

 malian order of the Edentata. 

 Buccal (Lat. bticca, mouth or cheeks). Connected Avith the mouth or 



cheeks. 

 Bvssus (Gr. bussos, flax). The silky threads by which many Bivalve Molluscs 



(such as the Mussels) attach themselves to foreign objects. 



Caducibranchiate (Lat. caducus, falling off; Gr. bragchia, gills). Applied 



to those Amphibians in which the gills fall off before maturity is reached 



(e g. , Newts and Progs). 

 C/ECAL (Lat. ccecus, blind). Terminating blindly, or in a closed extremity. 

 CAECUM (Lat. ccectts). A tube which ends in a blind extremity. 

 Calcareous (Lat. calx, lime). Composed of carbonate of lime. 

 Calice. The little cup in which the polype of a coral-producing Zoophyte 



(Actinozoon) is contained. 

 Calycophorid^ (Gr. kalux, a cup ; phero, I carry). An order of the Oceanic 



Hydrozoa, so called from their possessing bell-shaped swimming-organs. 

 Calyx (Lat. a cup). Applied to the cup-shaped body of the Bell-animalcule 



( Vorticella), or of the Vrinoidea, 

 Campanularida (Lat. campanula, a bell). A group of Sertularian Zoophytes. 

 Canine (Lat. canis, a dog). The eye-tooth in the jaw of Mammals ; so called 



because it is particularly well developed in Dogs and other carnivorous 



animals. 

 Carapace. A protective shield. Apjilied to the head-shield of Lobsters, 



Crabs, and many other Crustaceans ; and to the upper half of the bony case 



in which the Tortoises and Turtles are enclosed. 

 Carinat^ (Lat. carina, a keel). A sub-class of birds in which the breast-bone 



is keeled. 



