GLOSSARY. 403 



GANOID (Gr. ganos, splendour, brightness). Applied to those 

 scales or plates which are composed of an inferior layer of 

 true bone covered by a superior layer of polished enamel. 



GANOIDEI. An order of Fishes. 



GASTEROPODA (Gr. gaster, stomach; pous, foot). The class of 

 the Mollusca comprising the ordinary Univalves, in which 

 locomotion is usually effected by a muscular expansion of 

 the under surface of the body (the "foot"). 



GLOBIGERINA (Lat. globus, a globe; gero, I carry). A genus of 

 Foraminifera. 



GLYPTODON (Gr. glupho, I engrave; odous, tooth). An extinct 

 genus of Armadillos, so-named in allusion to the fluted teeth. 



GONIATITES (Gr. gonia, angle). A genus of Tetrabanchiate 

 Cephalopods. 



GRALLATORES (Lat. gralla, stilts). The order of the long-legged 

 Wading Birds. 



GRAPTOLITID^: (Gr. grapho., I write; lithos, stone). An extinct 

 sub-class of the Hydrosoa. 



GYMNOSPERMS (Gr. gumncs, naked; sperma, seed). The Conifers 

 and Cycads, in which the seed is not protected within a seed- 

 vessel. 



H 



HALITHERIUM (Gr. hals, sea; thtrion, beast). An extinct genus 



of Sea-cows (Sirenia}. 



HAMITES (Lat. hamus, a hook). A genus of the Ammonitidce. 

 HELIOPHYLLUM (Gr. helios, the sun; phullon, leaf). A genus 



of Rugose Corals. 

 HELLADOTHERIUM (Gr. HZllas, Greece; thVrion, beast). An 



extinct genus of Ungulate Mammals. 

 HEMIPTERA (Gr. hemi; and pteron, wing). An order of Insects 



in which the anterior wings are sometimes " hemelytra. " 

 HESPERORNIS (Gr. Hesperos, the evening star; ornis, bird). An 



extinct genus of Birds. 

 HETEROCERCAL (Gr. heteros, diverse; kerkos, tail). Applied to 



the tail of Fishes when it is unsymmetrical, or composed of 



two unequal lobes. 

 HETF.ROPODA (Gr. heteros, diverse; podes, feet). An aberrant 



group of the Gasteropods, in which the foot is modified so as 



to form a swimming organ. 

 HIPPARION (Gr. hipparion, a little horse). An extinct genus of 



E quid a. 

 HIPPOPOTAMUS (Gr. hippos, horse; potamos, river). A genus of 



hoofed Quadrupeds the " River-horses. " 

 HIPPURITID^: (Gr. hippos, horse; oura, tail). An extinct family 



of Bivalve Molluscs. 

 HOLOPTYCHIUS (Gr. holos, whole; ptuche*, wrinkle). An extinct 



genus of Ganoid Fishes. 

 HOLOSTOMATA (Gr. holos, whole; stoma, mouth). A division of 



Gasteropodous Molluscs, in which the aperture of the shell 



is rounded, or " entire. " 



