4 o6 GLOSSARY. 



MANDIBLE (Lat. mandibulum, a jaw). The upper pair of jaws 

 in Insects; also applied to one of the pairs of jaws in Crus- 

 tacea and Spiders, to the beak of Cephalopods, the lower jaw 

 of Vertebrates, etc. 



MANTLE. The external integument of most of the Mollusca, 

 which is largely developed, and forms a cloak in which the 

 viscera are protected. Technically called the " pallium. " 



MANUS (Lat. the hand). The hand of the higher Vertebrates. 



MARSIPOBRANCHII (Gr. marsipos, a pouch; bragchia, gill). The 

 order of Fishes comprising the Hag-fishes and Lampreys, with 

 pouch-like gills. 



MARSUPIALIA (Lat. marsupium, a pouch). An order of Mam- 

 mals in which the females mostly have an abdominal pouch 

 in which the young are carried. 



MASTODON (Gr. mastos, nipple; odous, tooth). An extinct genus 

 of Elephantine Mammals. 



MEGALONYX (Gr. megas, great; onux, nail). An extinct genus 

 of Edentate Mammals. 



MEGALOSAURUS (Gr. megas, great; saura, lizard). A genus of 

 Deinosaurian Reptiles. 



MEGATHERIUM (Gr. megas, great; thZrion, beast). An extinct 

 genus of Edentata. 



MESOZOIC (Gr. mesos, middle; and zoe, life). The Secondary 

 period in Geology. 



MICROLESTES (Gr. mikros, little; lestes, thief). An extinct genus 

 of Triassic Mammals. 



MILLEPORA (Lat. mille, one thousand; porus, a pore). A genus 

 of '"Tabulate Corals." 



MIOCENE (Gr. melon, less; kainos, new). The Middle Tertiary 

 period. 



MOLARS (Lat. mola, a mill). The "grinders" in man, or the 

 teeth in diphyodont Mammals which are not preceded by 

 milk-teeth. 



MOLLUSCA (Lat. mollis, soft). The sub-kingdom which includes 

 the Shell-fish proper, the Polysoa, the Tunicata, and the Lamp- 

 shells ; so-called from the generally soft nature of their 

 bodies. 



MOLLUSCOIDA (Mollusca; Gr. eidos, form). The lower division 

 of the Mollusca, comprising the Polysoa, Tunicata, and Brach- 

 iopoda. . 



MONOGRAPTUS (Gr. monos, single; grapho, I write). A genus 

 of Graptolites. 



MYLODON (Gr. mulos, a mill; odous, tooth). An extinct genus 

 of Edentate Mammals. 



MYRIAPODA or MYRIOPODA (Gr. murios, ten thousand; podes, 

 feet). A class of Arthropoda comprising the Centipedes and 

 their allies, characterized by their numerous feet. 



N 



NATATORES (Lat. nare, to swim). The order of the Swim- 

 ming Birds. 



NATATORY (Lat. nare, to swim). Formed for swimming. 

 NAUTILOID. Resembling the shell of the Nautilus in shape. 



