FISH OF ONTARIO. 107 



Articular. The bone of the mandible, supporting- the dentary. 



Articulate. Jointed. 



Artiodactylous. Even-toed (2 or 4). 



Atlas. The first vertebra. 



Atrophy. Non-development. 



Attenuate. Long and slender, as if drawn out. 



Auditory capsule. The ventrolateral swelling of the skull. 



Auricle. The large lobe of the external ear; also one of the chambers of 



the heart. 

 Axillars. Elongated feathers on the sides of the body under the wings. 



B. 



Band or bar. Any colour mark transverse to the long axis of the body. 



Barbel. An elongated fleshy projection usually about the head in fishes. 



Basal. Pertaining to the base ; at or near the base. 



Basibranchials. A lower median series of bones of the branchial arches. 



Basioccipital. A median posterior ventral bone of the skull to which the 

 atlas is attached. 



Basipterygoid. Bones developed in the palatine arch in some birds. 



Basis cranii. Formed by shelves of bone developed from the inner sides 

 of the prootics, which meet and form a root to the myodome and 

 a floor to the brain cavity. 



Beak. The bill of birds or (in other animals) any beak-like structure. 



Bend of wing. Angle at the carpus when the wing is folded. 



Bicolour. Two-coloured. 



Bicuspid. Having two points. 



Booted. Said of the tarsus in birds, when its scales coalesce and form a 

 continuous envelope, as in the Robin. 



Brachial ossicles. Synonymous with actinosts. 



Branchiae. Gills ; respiratory organs of fishes. 



Branchial. Pertaining to the gills. 



Branchihyals, Small bones at base of gill arches. 



Branchiostegals. The bony rays supporting the branchiostegal mem- 

 branes under the head of a fish, below the opercular bones and 

 behind the lower jaw. 



Bristle. A stiff hair, or hair-like feather. 



Buccal. Pertaining to the mouth. 



C. 



Caducous. Falling oft' early. 

 Cscal. Of the form of a blind sac. 



Caecum. An appendage of the form of a blind sac connected with the ali- 

 mentary canal. 



