GLOSSAllY. 371 



Metacarpus (Gr. meia, after ; l-arpos, tlie wristl The bones -wliicli form the 

 '* root of ihe liand," and intervene between the wrist and tlie fingers. 



MetamukphooIS (lir. meia, denoting change ; tnorphS, lornj). Tlie ciianges of 

 form wliich certain aniniais undergo in passing from their younger to their 

 fully-grown conditi 'U. 



Metatarsus (Gr. meta, after ; tarsus, the instep). The bones which intervene 

 between the instep (tarsus,) and the digits in the hind-foot of tlie liigher Ver- 

 tebrates. 



Metazoa (Gr. meta, beyond ; zniin, animal). A name applied collectively to 

 all animals excepi; the Protozoa, the latter being unicellular, while all other 

 animals are niulticellular. 



Molars (Lat. moto, a mill). The "grinders " in man ; or the teeth in Mam- 

 mals which are not preceded by milk-teeth. 



MoLLUSCA (Lat. mollis, soft). The sub-kingdom which includes the true 

 Shell-lish, the Polyzoa, the Sea-squirts, and the Lamp-shells. 



MoLLUSCOIDA {Mollusca, and Gr. eidos, form). The lower division of the 

 Molhisca, comprising the Polyzoa, the Sea -squirts [Tanicata), and the 

 Lamp-shells (Brachiopoda). 



MoKEKA (Gr. moneres, single). An order of Protozoa, comprising animals 

 composed of simple undifferentiated sarcode. 



MoNOTHALAMOUS (Gr. monos, single ; thalamos, a chamber). Consisting of 

 only a single chamber. Applied to the shells oi Foraviinifera and Mollusca. 



MoNOTREMATA (Gr. mofins, single : trema, an aperture). The order of Mam- 

 mals, comprising the Duck-mole and the Spiny Ant-eater, in which the in- 

 testinal canal opens into a " cloaca " common to the ducts of the urinary and 

 generative organs. 



Morphology {morphe, form ; logos, discourse). The science of the external 

 form and internal structure of the various parts and organs of diff'erent 

 animals. 



MuLTIVALVE (Lat. mul/us, many; valvie, folding-doors). Applied to shells 

 which are composed of more than two pieces or valves. 



MvRrAPODA (Gr. murios, ten thousand ; podes, feet). A class of Articulate 

 animals, comprising the Centipedes and their allies, characterised by the 

 possession of numerous feet. Often, and philologically more correctly, spelt 

 Mi/riopoda. 



Natatobes (Lat. nare, to swim). Tlie order of the Swimming Birds. 



Natatory. Adapted for swimming. 



Nautiloid. Shaped like the shell of the Nautilus. 



Nectocalyoes (Gr. necho, I swim ; kalux, a cup). The swimming-bells of 



the Oceania Hydrozoa. 

 Nematoda or Njematoidea (Gr. nema, a thread ; eidos, form). The division 



of the Scolecida comprising the Tnreatl-worms and Round-worms. 

 Nervures (Lat. nervus, a sinew). The ribs which support the membranous 



wings of insects. 

 Neural (Gr. neuron, a nerve). Connected with the nervous system. 

 Neuroptera (Gr. neuron, a nerve ; pteron, a wing). An order of Insects in 



which the wings are membranous and have numerous interlacing nervures. 

 Noctur:jal (Lat. nox, night). Applied to animals which are active at night. 

 Normal (Lat. norma, a rule). Conforming to the ordinary standard. 

 NOTOCHORD (Gr. nOtos, the back ; chorde, a string). A cellular rod which is 



developed in the embryo of Vertebrates immediately beneath the spinal cord, 



and which is usually replaced in the adult by the vertebral colninn. 

 Nucleolus. The minute solid particle found in the interior of the nucleus of 



some cells. Also the minute body attached to the exterior of the " nucleus " 



of certain of the Infusoria. 

 Nucleus (Lat. a kernel). The solid or vesicular body found in the interior of 



many cells ; also the solid rod, or band-shaped body, found in the interior of 



many of the Protozoa. 

 NUDIBRANCHIATA (Lat. nudus, naked ; Gr. Irragchia, gills). An order of the 



Gasteropoda in which the gills are naked. 



