210 University of Washington Publications in Biology [Vol. 2. 



Quadrate. A bone of the suspensorium on which the mandible is 

 hinged. 



Quincunx. Arrangements in sets of 5, thus, 



Ray. One of the cartilaginous rods supporting the membranes of the 

 fin. Rays are either spiny or soft, the latter are simple or branch- 

 ed. 



Recurved. Curved upward or backward. 



Reticulate. Marked with a network of lines. 



Retrorse. Turned backward. 



Rictus. The posterior corner of the mouth. 



Rostral plate. A small terminal plate on the tip of the snout. 



Rudimentary. Undeveloped. 



Rugose. Rough; wrinkled. 



Scales above the lateral line. The number of scales is counted for- 

 ward in an oblique row beginning at lateral line and running 

 anteriorly to just before the dorsal fin. 



Scaly appendage. The accessory scale which is a fleshy triangular 

 projection just dorsal to the ventral fin base on certain fishes. 



Scales below lateral line. The number of scales is counted in an ob- 

 lique row beginning at the anterior margin of the ventral fin 

 base and running forward or backward to the lateral line. 



Scale formida. A conventional formula, "scales 7+65 + 12", for ex- 

 ample, indicates seven scales in an oblique row above the lat- 

 eral line, sixty-five scales in the lateral line, and twelve in an 

 oblique series below the lateral line. 



Scales in lateral line. Usually the number of scales bearing tubes in 

 the lateral line or the number of oblique series (rows) along 

 the side of the fish. The scales are counted, beginning just a- 

 bove the opercular opening, to the end of the hypural plate of 

 the vertebral column, omitting the scales on caudal fin rays. 



Scapida. Shoulder blade ; in fishes, a bone of the shoulder girdle, the 

 upper bone of coracoid series. 



Scapidar arch. Shoulder girdle. 



Scute. Any external bony or horny plate, usually more or less spiny 

 or keeled. 



Second dorsal. The posterior of two fins, usually the soft rayed dor- 

 sal fin of "spiny rayed" fishes. 



Septum. Thin partition. 



Serrate. Notched like a saw. 



