Jordan and Evcrniann. — Fishes of North America. 2891 



Erectile. Susceptible of being raised or erected. 



Ethmoid. A median anterior bone of the sl^nll. 



Exoccipitals. Two bones of the skull, 1 on each side of the foramen 

 magnum. 



Exoskeleton. Hard parts (scales, scutes) on the surface of the body. 



Ejserted. Projecting beyond the general level. 



Extralimital. Beyond the limits (of this book). 



Facial. Pertaining to the face. 



Falcate. Scythe-shaped; long, narrow, and curved. 



Falciform. Curved, like a scythe. 



Fauna. The animals inhabiting any region, taken collectively. 



Femoral. Pertaining to the femur, or jjroximal bone of the hinder leg. 



Filament. Any slender or .thread-like structure. 



Filiform. Thread form. 



Fontanel. An unossificd space on top of head covered with membrane. 



Foramen. A hole or opening. 



Foramen mannum. The aperture in the posterior part of the skull for the 

 passage of the spinal cord. 



Forehead. Frontal curve of head. 



Forficate. Deeply forked; scissors-like. 



Fossd' (nasal). Groves in which the nostrils open. 



Frontal bone. Anterior bone of top of head, usually paired. 



Fulcra. Rudimentary spine-like projections extending on the anterior rays 

 of the tins of ganoid fishes. 



Furcate. Forked. 



Fusiform. Spindle-shaped; tapering toward both ends, 1)ut rather more 

 abruptly forward. 



Ganf/lion. A nerve center. 



Ganoid. Scales or plates of bone covered by enamel. 



Gape. Opening of the mouth. 



Gill arches. The bony arches to which the gills are attached. 



Gill openings. Openings leading to or from the branchiie. 



Gill rakers. A series of bony appendages, variously formed, along the inner 

 edge of the anterior gill arch. 



Gills. Organs for breathing the a^r contained in water. 



Glabrous. Smooth. 



Glossohijal. The tongue bone. 



Graduated (spines). Progressively longer backward, the third being as 

 much longer than the second as second is longer than tirst. 



Granulate. Rough with small prominences. 



Gular. Pertaining to the gula, or upper foreneck. 



Hamal arch. An arch under a ha-mal spine for the passage of a blood 

 vessel. 



Hwrnal canal. The series of lia'mal arches as a whole. 



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



Hwmopophijses. Appendages on the lower side of abdominal vertebra, in 

 fishes. 



Height. Vertical diameter. 



Heterocercal. Said of the tail of a fish when unequal; the backbone evi- 

 dently running into the upper lobe. 



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

 backbone apparently stopping at the middle of the base of the cau- 

 dal fin. 



Humerus. Bone of the upper arm. 



Hijoid. Pertaining to the tongue. 



Hijoid apparatus. Formed by a series of bones extending along the inner 

 side of the mandible and supporting the tongue. 



Hyomandibular. A bone by which the posterior end of the suspensnrium 

 is articulated with the skull; the supporting element of the suspenso- 

 rium, the mandible, the hyoid apparatus, and the opercular apparatus. 



Hypercoracoid. The upper of the 2 bones attached to the clavicle, indi- 

 rectly bearing the jiectoral fin. 



