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POPULAK CONCHOLOGY. 



Filiform, Filamentary. Thread-like. 

 Fimbriated. Fringed. 

 Fluviatile. Living in fresh water. 



Foliated. Composed of thin plates, lying on each other, as in the 



shell of the oyster. 

 Foramen. A slit. 

 Furcated. Forked. 



Fusiform. Shaped like a spindle, swollen in the middle, and tapering 

 to each end. 



Gaping. In Bivalves, when, the shell being closed, the valves do not 



touch each other in every part. 

 Gelatinous. Like jelly. 



Hamate. Scythe-shaped. 

 Hastate. Spear-shaped. 



Hinge. The part where the valves of a Bivalve are united, consisting 

 of ligament and teeth, the portion on which they are situated 

 being called the hinge lamina, or line. 



Hyaline. Of a glassy, thin, and semi-transparent substance. 



Imbricated. Lying over each other like tiles. 



Inequilateral. When the sides of a Bivalve are unequal in length. 



(See Equilateral.') 

 Inequivahe. When the valves of a Bivalve are unequal in size and 



shape, as the oyster. (See Equivalve.) 

 Inferior Valve. In adherent Bivalves, that by which the shell is 



attached to other substances. 

 Involuted. Rolled in. 



Iridescent. Pearly, or having the appearance of pearl. 

 Irregular. In Bivalves, when the individuals of a species are not all 

 of the same shape. 



Laminar. Formed of thin plates. 

 lanceolate. Shaped like the head of a lance. 



lateral. Any thing on the sides of a shell. Thus the lateral teeth 

 of Bivalves, where they exist, are on one or both sides of the 

 cardinal teeth, which are always in the centre, under the bosses. 



Length of Shells. Spiral shells are measured from the apex, or tip of 

 the spire to the base, and therefore perpendicularly ; but the 



