GLOSSARY. 405 



INVERTEBRATA (Lat. in, without; vertebra, a bone of the back). 

 Animals without a spinal column or backbone. 



ISOPODA (Gr. isos, equal; podes, feet). An order of Crusta- 

 cea in which the feet are like one another and equal. 



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KAINOZOIC (Gr. kainos, recent; zoe, life). The Tertiary period 

 in Geology comprising those formations in which the organic 

 remains approximate more or less closely to the existing fauna 

 and flora. 



LABYRINTHODONTIA (Gr. laburinthos, a labyrinth; odous, tooth). 

 An extinct order of Amphibia, so-called from the complex 

 microscopic structure of the teeth. 



LACERTILIA (Lat. lacerta, a lizard). An order of Reptilia com- 

 prising the Lizards and Slow-worms. 



LAMELLIBRANCHIATA (Lat. lamella, a plate; Gr. bragchia, gill). 

 The class of Mollusca comprising the ordinary bivalves, char- 

 acterized by the possession of lamellar gills. 



LEPIDODENDRON (Gr. lepis, a scale; dendron, a tree). A genus of 

 extinct plants, so-named from the scale-like scars upon the 

 stem left by the falling off of the leaves. 



LEPIDOPTERA (Gr. lepis, a scale; pteron, a wing). An order of 

 Insects, comprising Butterflies and Moths, characterized by 

 possessing four wings which are usually covered with minute 

 scales. 



LEPIDOSIREN (Gr. lepis, a scale; seiren, a siren the generic name 

 of the Mud-eel or Siren lacertina). A genus of Dipnoous 

 fishes, comprising the " Mud-fishes. " 



LEPIDOSTROBUS (Gr. lepis. a scale; strobilos, a fir-cone). A genus 

 founded on the cones of Lepidodendron. 



LEPT^NA (Gr. leptos, slender). A genus of Brachiopods. 



LINGULA (Lat. lingula, a little tongue). A genus of Brachio- 

 pods. 



LYCOPODIACE^: (Gr. lupos, a wolf; pous, foot). The group of 

 Cryptogamic plants generally known as " Club-mosses. " 



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MACH^RACANTHUS (Gr. machaira, a sabre ; acantha, thorn or 

 spine). An extinct genus of Fishes. 



MACHAIRODUS (Gr. machaira, a sabre; odous, tooth). An ex- 

 tinct genus of Carnivora. 



MACROTHERIUM (Gr. makros, long; therion, beast). An extinct 

 genus of Edentata. 



MACRURA (Gr. makros, long; oura, tail). A tribe of Decapod 

 Crustaceans with long tails (e. g., the Lobster, Shrimp, etc.) 



MAMMALIA (Lat. mamma, the breast). The class of Verte- 

 brate animals which suckle their young. 



