GLOSSARY. 165 



Gemmation (Lat. gemma, a bud) A method of reproduction by 



which new individuals are formed from buds which arise on 



the body of the parent. 

 Gemmule (Lat. a little bud) A minute mass of spongy particles 



covered with a cyst. 

 Gizzard A part of the stomach of birds, insects, &c., furnished 



with muscular walls. 

 Globigerina (Lat. globus, a ball; gcro, I carry) A group of Fora- 



mini/era, found abundantly in chalk. 

 Graptolites (Gr. grapho, I write ; lithos, a stone) An extinct 



group of ffydrfiioa, whose remains are found in the Silurian 



strata. 



Gregarinida (Lat. grex, a flock) A class of Protozoa. 

 Guard The fibrous sheath which protects the phragmacone of 



the Belemnite. 



i- Haemal (Gr. haima, blood) Belonging to the blood. 



Hectocotylus (Gr. hekaton, a hundred; kotulos, a cap) One of the 

 arms of the male cuttle-fishes modified into a reproductive 

 organ. 



Hemimetabolic (Gr. hemi, half ; meldbole, change) Insects which 

 undergo incomplete metamorphosis. 



Hermaphrodite (Gr. Hermes, Mercury; Aphrodite, Venus) Having 



the sexes combined in the same individual. 



i^ileterocercal (Gr. heteros, different; kerkos, a tail) Applied to 

 the caudal or tail fin of fishes when the two lobes are 

 unequal. 



Heterophagi (Gr. heteros, different; phago, I eat) A term applied 

 to birds which come from the egg in a helpless state, requir- 

 ing to be fed for a time by the parents. 



Holometabolic (Gr. holos, whole; metabole, change) A term ap- 

 plied to insects whose metamorphosis is complete. 



Holostomata (Gr. holos, whole; stoma, mouth) A group of Gastero- 

 poda, in which the aperture of the shell is not furnished 

 with a notch or canal. 

 ^Homocercal (Gr. homos, like; kerfcos, tail) A term applied to the 



tail fins of fishes which are divided into two equal lobes. 

 . Humerus The bone which connects the radius with the pectoral 

 arch in vertebrates. 



Hydrosoma (Gr. hudra, a water dragon; soma, body) The entire 

 body of a hydrozoon, whether simple or compound. 



HydrothecsB (Gr. hudra; theka, a case) The horny cups inhabited 

 by the sertularian polypites. 



Hydrozoa (Gr. hudra; zoon, an animal) A class of Codmterata, 



exemplified by the fresh-water hydra and jelly-fishes. 

 UHyoid The tongue bone, so called because in man it is shaped 

 like the letter U. 



