2896 Bulletin 4.7, United States National Museum. 



Suture. The line of union of 2 bones, as in the skull. 



Symphysis. Point of junction of the 2 parts of lower jaw; tip of chin. 



Symplectic. The bone in fishes that keys together the hyomandibular and 



quadrate posteriorly. 



Synonym. A different word having the same or a similar meaning. 

 Synonymy. A collection of different names for the same group, species, or 



thing; "A burden and a disgrace to science." (Cones.) 

 Tail. In fishes (usually), the part of the body posterior to the anal fin. 



(Often used more or less vaguely.) 

 Temporal. Pertaining to the region of the temples. 

 Terete. Cylindrical and tapering. 

 'Terminal. At the end. 



Tessellated. Marked with little checks or squares, like mosaic work. 

 Thoracic. Pertaining to the chest ; ventral fins are thoracic when attached 



immediately below the pectorals, as in the perch, the pelvic bones 



being fastened to the shoulder girdle. 

 Transverse. Crosswise. 

 Trenchant. Compressed to a sharp edge. 

 Truncate. Abrupt, as if cut squarely off. 

 Tubercle. A small excrescence, like a pimple. 

 Type (of a genus). The species upon which was based the genus to which 



it belongs. 

 Type (of a species). The particular specimen, upon which the original 



specific description was based. 

 Type locality. The particular place or locality at which the type specimen 



was collected. 



Typical. Of a structure the most usual in a given group. 

 Ultimate. Last or farthest. 

 Unicolor. Of a single color. 



Vent. The external opening of the alimentary canal. 

 Ventral. Pertaining to the abdomen. 

 Ventral fins. The paired fins behind or below the pectoral fins in fishes, 



corresponding to the posterior limbs in the higher vertebrates. 

 Ventral plates. In serpents or fishes, the row of plates along the belly be- 

 tween throat and vent. 



Ventricle. One of the thick- walled chambers of the heart. 

 Versaiile. Capable of being turned either way. 

 Vertebra. One of the bones of the spinal column. 

 Vertical. Up and down. 

 Vertical fins. The fins on the median line of the body ; the dorsal, anal, 



and caudal fins. 

 Villiform. Said of the teeth of fishes when slender and crowded into 



velvety bands. 

 Viscous. Slimy. 



Viviparous. Bringing forth living young. 

 Vomer. In fishes, the froi-t part of the roof of the month; a bone lying 



immediately behind the premaxillaries. 



Zygapophyses. Points of bone affording to the vertebra; more or less defi- 

 nite articulation with each other. 



