THE NATURAL HISTORY SURVEY. 385 
Gelatinous. Like jelly, as the eggs of some mollusks. 
Gibbous. Very much rounded, as the whorls in some snails (pl. xxxvi, 
fig. 1). 
Glandular. Like a gland. 
Globose. Rounded. 
Granulated. Covered with little grains. 
Gravid. A female mollusk (as Unio) with ovaries distended with young: 
Gregarious. Living in colonies. 
Gular. Relating to the windpipe or palate. In mollusks, referring to 
the innermost part of the aperture. 
Habitat. Locality of a species. 
Hemolymph. Molluscan blood. 
Heliciform. In form like Helix. 
Hemispherical. Half a sphere. 
Herbivorous. Subsisting upon vegetable food. 
Hermaphrodite. Having the sexes united in the same individual. 
Hibernation. The act of hibernating or going to sleep for the winter 
months. 
Hirsute. Covered with hairs, as some snails. 
Hispid. Same as hirsute. 
-Homologous. Having the same position or value, as the wing of a bird 
and of a bat. 
Hyaline. Glassy. 
Imperforate. Not perforated or umbilicated (pl. xxix, fig. 8). 
Impressed. Marked by a furrow, as the impressed spiral lines on 
some univalve shells. 
Incequipartite. When one end of a shell is longer than the other, as 
the two ends in Pisidium. 
Incrassate. Thickened. 
Incurrent. The siphon in Unio which brings in the food-stuffs. 
Incurved. Leaned or bent over, as the apex in some snails. 
Indented. Notched. 
Inequivalve. When one valve is larger than the other. 
Inflated. Swollen, as some bivalve shells (pl. iii, fig. 2). 
Inflected. Turned in, as the teeth of some snails. 
Inhalent. Same as incurrent. 
Inoperculate. Without an operculum. 
Intercostate. Between the ribs or ridges. 
Invaginate. One part bending into another, as the tentacles of some 
land snails. 
Invertible. Capable of being inverted, or drawn in, as the eye-pedun- 
cles of a land snail. 
Keeled. With amore or less sharp projection at the periphery (pl. 
xxvi, fig. 5). 
Labial. Pertaining to the lips, asthe labial-palpi in Unio. 
Lamellated. Covered with scales. 
Lamelliform. Having the form of scales. 
Laminated. Consisting of plates or scales laid over each other. 
