GLOSSARY OF TECHNICAL TERMS. 367 



Gonys. The middle line of the lower mandible. 



Gorget. Throat patch of peculiar feathers. 



Graduated (spines). Progressively longer backward; the third being 



as much longer than second as second is longer than first. 

 Graduated (tail). One in which the outer feathers are regularly shorter 



from the middle. 

 Granulate. Kough with small prominences. 

 Gular. Pertaining to the gula, or upper fore-neck. 

 Hcemal spine. The lowermost spine of a caudal vertebra, in fishes. 

 Hxmopophyses. Appendages on the lower side of abdominal vertebrae, 



in fishes. 

 Hallux. The great toe, — in birds, the hind toe. 

 Height. Vertical diameter. 

 Heterocercal. Said of the tail of a fish, when unequal, — the back-bone 



evidently running into the upper lobe. 

 Hirsute. With shaggy hairs. 

 Homocercal. Said of the tail of a fish when not evidently unequal ; the 



back-bone apparently stopping at the middle of the base of the 



caudal fin. 

 Humerus. Bone of the upper arm. 

 Hyoid. Pertaining to the tongue. 

 Hypognathous. Having the lower mandible longer than the upper, as 



in the Black Skimmer. 

 Imbricate. Overlapping, like shingles on a roof. 

 Imperforate. Not pierced through. 

 Inarticulate. Not jointed. 

 Incisors. The front or cutting teeth. 

 Infraoral. Below the mouth. 

 Interfemoral membrane. The membrane connecting the posterior limbs 



of a bat. 

 InterhcemaJs. Bones to which anal rays are attached in fishes. 

 Intermaxillaries. The premaxillaries ; the bones forming the middle 



of the front part of the upper jaw, in fishes. 

 Internasals. Plates on the forehead of the snake on the line connecting 



the two nostrils. 

 Interneurals. Bones to which dorsal rays are attached in fishes. 

 Interopercle. Membrane bone between the preopercle and the branchi- 



ostegals. 

 Interorbital. Space between the eyes. 

 Interspinals. Bones to which fin-rays are attached (in fishes) ; inserted 



between neural spines above and haemal spines below. 

 Isocercal (tail). Last vertebrae progressively smaller and ending in 



median line of caudal fin, as in the Cod-fish. 

 Jugular. Pertaining to the lower throat, — said of the ventral fins, 



when placed in advance of the attachment of the pectorals. 

 Keeled. Having a ridge along the middle line. 

 Labials. Plates forming the lip of a serpent. 

 Lamellce. Plate-like processes inside of the bill of a duck. 

 Lamellate. Said of a bill provided with lamellse, as in a duck. 



