GLOSSARY OF TECHNICAL TERMS CXXXl 



Glossary of Anatomical and other Technical Terms* 



Abdominal ventral fins. Ventrals which are inserted posteriorly, the pelvic bones having no 

 connection with shoulder girdle. (See key to families, b, note, p. L) 



Acanthopterygian. Spiny rayed. Said of the numerous families of fishes related to the basses 

 and perches, in which part or all of the rays of at least one dorsal fin and the first ray of the 

 ventral fins are of a spinous (unarticulated) character. (See spine and ray.) 



Accessory caudal rays. Short, procurrent rays on the upper and lower (rather than posterior) 

 part of the caudal peduncle. 



Accessory pectoral scale. An enlarged scale at the base of the pectoral fin in certain herring-like 

 fishes. 



Actinosts. Small bones at the base of the paired fins. 



Adipose fin. A fleshy fin-like structure behind the dorsal fin, as in^salmons and catfishes. This 

 is sometimes more or less continuous with the caudal fin, being separated from it only by 

 a notch. 



Air-bladder. A sac filled with air or other gases, lying beneath the backbone, and either adherent 

 or not to the walls of the visceral cavity. It may be simple (most teleosts) or divided into 

 compartments by constrictions {Catostomidm and Cyprinidce) or of a cellular structure 

 (some Ganoidn) . It is typically c onnected with the oesophagus by a duct, which is closed 

 in many recent forms. 



Ammocaetes. A name applied to the larval form of lampreys 



Amphicoelian Concave both before and behind. Said of the vertebrae of fishes generally, 

 with the except on of certain forms. (See opisthocaelian.) 



Anadromous. Running up rivers from the sea to spawn, as do shad and some sahnonoids. 



Anal. Pertaining to the anus, or vent. 



Anal fin. The fin on the median line behind the vent. (Fig. 1, a ) 



Anal papilla. A protuberance, usually bilobed, in front of the genital pore and behind the 



vent in darters and sculpins. 

 Angidar. A bony element of the lower jaw. 

 Antrwse. Directed forward. 



Anus. The posterior external opening of the alimentary canal; the vent. 

 Arterial bulb. (See conus arteriosus.) 

 Articular. A bony element of the lower jaw. 

 Articulated. Jointed. (See ray.) 

 Auditory ossicles. (See Weberian ossicles.) 



Barbel. An elongated, feeler-like projection, usually about the mouth, chin, or nose, as in the 

 carp, and in catfishes. 



Branchial. Of the gills (branchioe). 



Branchiostegals. Bony rays supporting the membranes which close the branchial cavity below. 



(Fig. 1, br.) 

 Buccal. Of the mouth. 

 Caducous. Falling off. Said of certain plate-like scales on the belly of darters. 



*In the preparation of this glossary-, that of Jordan's Manual of the Vertebrates (ed. 8) 

 has been of substantial assistance, and, naturalh', some of the definitions will be found to be 

 the same. In addition, however, a good many new terms have been inserted, and many old 

 definitions amended, applied to particular cases, extended to more informative dimensions, or 

 simplified by reference to figures. 



