THE SHORE FISHES OF PERU H 



Barbel. — An elongate, fleshy projection, or "whisker," usually about the head. 



Branchiae.- — The gills. 



Branchial. — Pertaining to the gills, as branchial arches, the bony supports of the 



gill filaments. 

 Branchiostegals. — Bony rays or arches under the head and below the opercular 



bones, supporting the branchiostegal membranes. 

 Cirri. — Dermal fringes. 



Claspers.— Organs attached to the ventral fins in male sharks, rays, etc. 

 Compressed. — Flattened from side to side; said of fishes that are deeper than broad. 

 Ctenoid. — With rough edges; said of scales with spinous or pectinate posterior 



edges. 

 Cycloid.' — With smooth edges; said of scales with smooth posterior edges. 

 Dentary. — The principal bones of the lower jaw or mandible, usually bearing 



teeth. 

 Denticles.' — Little teeth, such as occur on the skin of a shark. 

 Depressed. — Flattened vertically; said of fishes that are broader than deep. 

 Distal. — Remote from the place of attachment. 

 Emarginate. — Slightly forked or notched ; often used in describing the shape of the 



caudal fin. 

 Falcate. — Scythe-shaped; long, narrow, and curved; sometimes used to describe 



the shape of the pectoral fin. 

 Filament. — A slender, threadlike structure. 

 Fontanel. — An opening between the bones of the skull. 

 Gill rakers. — A series of bony projections placed along the inner edge of the 



branchial or gill arch. 

 Imbricate. — Overlapping; said of scales that overlap like shingles on a roof. 

 Isthmus. — The area between the lower part of the gill opening, or the anterior 



part of the chest, usually more or less pointed anteriorh\ 

 Jugular. — Pertaining to the throat; said of ventral fins if attached in advance 



of the pectorals. 

 Xee/ed.— Having a ridge, as along the side of the tail in some groups of fishes. 

 Lateral line. — A series of pores along the side, containing sense organs. 

 Mandible. — Lower jaw, 

 Maxillaries.- — The outer bones of the upper jaw, joined to the premaxillaries in 



front of them, sometimes bearing teeth. 

 Myomeres. — Muscle segments or rings. 



Nape. — Pertaining to the neck, that is, the region immediately behind the head. 

 Nictitating membrane. — An inner eyelid, as in some sharks among the fishes. 

 Nuchal. — Pertaining to the nape or neck. 

 Obsolete. — Faintly marked; scarcely evident. 

 Ocellus. — An eyelike spot; a dark spot with a light border. 

 Opercle. — The thin bone on the side of the head, covering the gills. 

 Palatines. — A pair of bones in the roof of the mouth, extending outward and 



backward from the vomer, sometimes bearing teeth. 

 Pharyngeal bones. — Bones behind the gills and at the beginning of the esophagus, 



often bearing teeth. 

 Premaxillaries. — The bones, one on each side, forming the front of the upper jaw; 



usually bearing teeth. 

 Preopercle.- — ^A thin bone lying on side of head just in front of the opercle. 

 Preorbiial. — The bone lying just in front of and somewhat below the eye. 

 Protractile. — Capable of being drawn forward; said of the premaxillaries, if not 



stationary. 

 Pseudobranchiae. — Small gills developed in some fishes on the inner side of the 



opercle. 



