GLOSSARY. 571 



EPIMERA (Gr. epi, upon ; meron, thigh). The lateral pieces of the dorsal arc 



of the somite of a Crustacean. 

 EPIPODIA (Gr. epi, upon ; pous, the foot). Muscular lobes developed from 



the lateral and upper surfaces of the " foot" of some Molluscs. 

 EPIPODITE (Gr. epi, upon; pous, foot). A process developed upon the basal 



joint, or " protopodite," of some of the limbs of certain Crustacea. 

 EPISTERNA (Gr. epi, upon ; sternon, the breast-bone). The lateral pieces of 



the inferior or ventral arc of the somite of a Crustacean. 

 EPISTOME (Gr. epi ; and stoma, mouth). A valve-like organ which arches 



over the mouth in certain of the Polyzoa. 

 EPITHECA (Gr. epi; and theke, a sheath). A continuous layer surrounding 



the thecre in some Corals externally. 

 EPIZOA (Gr. epi, upon ; zoon, animal). Animals which are parasitic upon 



other animals. In a restricted sense, a division of Crustacea which are 



parasitic upon fishes. 

 EQUILATERAL (Lat. cequus, equal ; latus, side). Having its sides equal. 



Usually applied to the shells of the Brachiopoda. When applied to the 



spiral shells of the Foraminifera, it means that all the convolutions of the 



shell lie in the same plane. 

 EQUISETACEA (Lat. eyuus, horse ; seta, bristle). A group of Cryptogamous 



plants, commonly known as " Horse-tails." 

 EQUIVALVE (Lat. cequus, equal; valvce, folding-doors). Applied to shells 



which are composed of two equal pieces or valves. 

 ERRANTIA (Lat. erro, I wander). An order of Annelida, often called Nereidea, 



distinguished by their great locomotive powers. 

 EURYPTERIDA (Gr. eurus, broad ; pteron, wing). An extinct sub-order of 



Crustacea. 

 EXOPODITE (Gr. exo, outside ; pous, foot). The outer of the two secondary 



joints into which the typical limb of a Crustacean is divided. 

 EXOSKELETON (Gr. exo, outside ; skeletos, dry. The external skeleton, which 



is constituted by a hardening of the integument, and is often called a 



" dermoskeleton." 



FASCICULATED (Lat. fasciculus, a bundle). Arranged in bundles. 



FAUNA (Lat. Fauni, the rural deities of the Romans). The general assem- 

 blage of the animals of any region or district. 



FEMUR. The thigh-bone, intervening between the pelvis and the bones of 

 the leg proper (tibia and fibula). 



FIBULA (Lat. a brooch). The outermost of the two bones of the leg in the 

 higher Vertebrata ; corresponding to the ulna of the fore-arm. 



FILICES (Lat. filix, a fern). The order of Cryptogamic plants comprising the 

 Ferns. 



FILIFORM (Lat. filum, a thread ; forma, shape). Thread-shaped. 



FISSION (Le&.findo, I cleave). Multiplication by means of a process of self- 

 division. 



FISSIPAROUS (Lat. findo ; and pario, I produce). Giving origin to fresh struc- 

 tures by a process of fission. 



FLORA (Lat. Flora, the goddess of flowers). The general assemblage of the 

 plants of any region or district. 



FOOT-JAWS. The limbs of Crustacea, which are modified to subserve mastica- 

 tion. 



FOOT- SECRETION. The term applied by Mr Dana to the sclerobasic corallum 

 of certain A ctinozoa. 



FOOT-TUBERCLES. The unarticulated appendages of the Annelida, often 

 called parapodia. 



FORAMINIFERA (Lat. foramen, an aperture ; fero, I carry). An order of Pro- 

 tozoa, usually characterised by the possession of a shell perforated by 

 numerous pseudopodial apertures. 



FRUGIVOROUS (L&t.fruz, fruit; voro, I devour). Living upon fruits. 



FUCOIDS (Lat. fucus, sea- weed; Gr. eidos, likeness). Fossils, often of an 

 obscure nature, believed to be the remains of sea-weeds. 



