GLOSSARY OF TECHNICAL TERMS CXXV 



Glossary of Anatomical and other Technical Terms* 



Abdominal ventral fins. Ventrals which are inserted posteriorly, the pelvic bones 

 having no connection with the shoulder girdle. (See key to families, b, 

 note, p. 1.) 



Acanthoptcrygian. 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 hn, 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 (Catostomidce 

 and Cyprinidce) or of a cellular structure (some Ganoidei). It is typically con- 

 nected with the oesophagus by a duct, which is closed in many recent forms. 



AmmoccBtes. A name applied to the larval form of lampreys. 



Amphiccelian. Concave both before and behind. Said of the vertebrae of fishes 

 generally, with the exception of certain forms. (See opisthocoelian.) 



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

 monoids. 



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 be- 

 hind the vent in darters and sculpins. 

 Angular. A bony element of the lower jaw. 

 Antrorse. Directed forward. 



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

 Arterial bidb. (See conns arteriosus.) 

 Artie idar. 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 {branchice). 



Branchiostegals . Bony rays supporting the membranes which close the branchial 

 cavity below. (Fig. 1, br.) 



*In the preparation of this glossary, that of Jordan's Manual of the Vertebrates 

 (ed. 8) has been of substantial assistance, and, naturally, 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. 



