GLOSSARY 257 
Fungi: A group of lowly plants, including mushrooms, moulds, 
and bacteria. 
Galls ; Growths on plants caused by insects or fungi. 
Ganoids : The earliest known type of fishes, having defensive 
armour. 
Gasteropoda: A group of molluscs which creep on a broad 
expansion of the body which serves as a foot (snails). 
Geology : The science of the earth, its formation, development, 
and history. 
Glumes : Scales or bracts of grasses and sedges. 
Glumacese : A sub-class of plants, including the grasses and 
sedges. 
Gneiss : A metamorphic rock. 
Granite : A crystalline Plutonic rock. 
Graphite: A black, opaque mineral, composed of nearly pure 
carbon. 
Graptolites : A group of Paleozoic organisms. 
Grit : A sandstone, composed of coarse, angular quartz fragments. 
Gymnosperms: Plants bearing naked ovules, without styles or 
stigmas. 
Gypsum : A mineral composed of hydrous sulphate of calcium. 
Hamites : A variety of fossil cephalopods. 
Hastate : The shape of a spear-head. 
Herbarium : A collection of preserved plants. 
Hibernate : To pass the winter in a state of sleep or torpor. 
Horizon : In geology, a bed or number of beds of strata in which 
typical fossils occur. 
Hybrid : A mule or mongrel, a plant produced from two different 
species. 
ee : Hyposulphite of soda, used in photography. 
Ichthyosaurs : A group of extinct fish-lizards. 
Igneous : Produced by the action of heat. 
Iguanadon : An extinct reptile. 
Imparipinnate : Leaflets of pinnate leaves arranged in pairs with 
an odd terminal leaflet. 
Inflorescence : Flower arrangement. 
Insectivorous : Feeding on insects. 
Invertebrate : Without a backbone or vertebral column. 
Involuecre : Bracts arranged in a whorl at the base of a single 
flower, an umbel or a head of flowers. 
Jurassic : The second system of Mesozoic rocks. 
Labellum : The lower lip of the flowers of orchids. 
Labyrinthodonts : A group of extinct amphibians. 
Lamellibranchia : Bivalve molluscs, like the cockle and oyster. 
Lamina : The blade of a leaf, petal, etc. 
Lanceolate : Lance-shaped. 3 
