510 GLOSSARY. 



Corymb. — A biincli of flowers in which those springing from the 

 lower part of the flower-stalks are supported on long stalks so as 

 to be nearly on a level with the upper ones. 



Cotyledons. — The first or seed-leaves of plants. 



Crustaceans. — A class of articulated animals, having the skin of 

 the body generally more or less hardened by the deposition of 

 calcareous matter, breathing by means of gills. {Examples, 

 Crab, Lobster, Shrimp, etc.) 



CuRCULio. — The old generic term for the Beetles known as Weevils, 

 characterized by their four jointed feet, and by the head being 

 produced into a sort of beak, upon the sides of which the 

 antennaD are inserted. 



Cutaneous. — Of or belonging to the skin. 



Degradation. — The wearing down of land by the action of the sea 

 or of meteoric agencies. 



Denudation. — The wearing away of the surface of the land by 

 water. 



Devonian System or Formation. — A series of Palaeozoic rocks, 

 including the Old Red Sandstone. 



Dicotyledons or Dicotyledonous Plants. — A class of plants 

 characterized by having two seed-leaves, by the formation of new 

 wood between * the bark and the old wood (exogenous growth) 

 and by the reticulation of the veins of the leaves. The parts of 

 the flowers are generally in multiples of five. 



Differentiation. — The separation or discrimination of parts or 

 organs which in simpler forms of life are more or less united. 



Dimorphic. — Having tv/o distinct forms. — Dimorphism is the condi- 

 dition of the appearance of the same species under two dissimilar 

 forms. 



Dicecious. — Having the organs of the sexes upon distinct indi- 

 viduals. 



DiORiTE. —A peculiar form of Greenstone. 



Dorsal. — Of or belonging to the back. 



Edentata. — A peculiar order of Quadrupeds, characterized by the 



absence of at least the middle incisor (front) teeth in both jaws. 



{Examples, the Sloths and Armadillos.) 

 Elytra. — The hardened fore- wings of Beetles, serving as sheaths 



for the membranous hind-wings, which constitute the true 



organs of flight. 

 Embryo. — The young animal undergoing development within the 



egg or womb. 

 Embryology. — The study of the development of the embryo. 

 Endemic. — Peculiar to a given locality. 

 Entomostraca. — A division of the class Crustacea, having all the 



segments of the body usually distinct, gills attached to the feet 



or organs of the mouth, and the feet fringed with fine hairs. 



They are generally of small size. 

 Eocene. — The earliest of the three divisions of the Tertiary epoch 



of geologists. Rocks of this age contain a small proportion of 



shells identical with species now living. 



