788 Bulletin 47, United States National Museum. 



This group comprises 4canthopteri, with the ventral fins abdominal, 

 each of I spine and 5 rays, and the pelvic bones not attached to the 

 shoulder girdle; the spinous armature of the fins is less developed, 

 the scales are cycloid, and the opercles unarmed. The suborder marks a 

 transition from soft-rayed to spiny-rayed fishes, its nearest associates 

 among the latter being, perhaps, the Scombroid forms. The families here 

 defined are closely related, but whether other families, as Ophiocephalidce, 

 Ammodytidce, etc., should be included, is not certain. From fishes of the 

 general character of Percesoces, the Hemibranchii and Lophobranchii seem 

 to be descended, and the Synentognathi are closely allied. The group is 

 composed chiefly of shore fishes and fresh-water fishes, mostly of small 

 size but some of them large and voracious. (Perca, Perch; Esox, Pike.) 



a. Lateral line wanting; teeth small or wanting; gill rakers long and slender. 



b. Species carnivorous, the body and head elongate; vertebrae more than 35; dorsal spines 



slender, flexible, 3 to 8 in number; stomach not gizzard Jike. ATHERINIDJS, cvi. 



bb. Species feeding on mud and vegetation; the head short and broad; .vertebras about 24; 



stomach gizzard-like, with long intestines. MUGILIDJE, cvn. 



aa. Lateral line present; teeth very strong, unequal; gill rakers obsolete; head long and 



pointed; vertebrae about 24. SPHYB^NID^;, cvm. 



Family CVI. ATHERINID^. 



(THE SlLVERSIDES. ) 



Body rather elongate, somewhat compressed, covered with scales of 

 moderate or small size, which are usually, but not always, cycloid. No 

 lateral line ; some scales often with rudimentary mucous tubes. Cleft 

 of the mouth moderate. Teeth small, on jaws and sometimes on vomer 

 and palatines, rarely wanting. Premaxillaries protractile or not. Oper- 

 cular bones without spines or serrature. Gill openings wide, the gill 

 membranes not connected, free from the isthmus ; gills 4, a slit behind 

 the fourth. Pseu dobranchi se present ; gill rakers usually long and slen- 

 der. Branchiostegals 5 or 6. Dorsal fins 2, well separated, the first of 3 

 to 8 slender flexible spines, the second of soft rays ; anal with a weak 

 spine, similar to the soft dorsal, but usually larger ; ventral fins small, 

 abdominal, not far back, of 1 small spine and 5 soft rays; pectorals 

 moderate, inserted high. Air bladder present. No pyloric cceca. Verte- 

 brae numerous, usually about 23 + 23 = 46; third and fourth superior 

 pharyngeals coossified, with teeth. Carnivorous fishes, mostly of small 

 size, living in great schools near the shore in temperate and tropical 

 seas ; a few species in fresh water ; all the species have a silvery band 

 along the side ; this is sometimes underlaid by black pigment. Genera 

 about 15 ; species 60. All of them which are large enough are highly 

 valued as food, hence the common name of " fishes of the king," Pesca- 

 dos del Rey, or Pesce Re, or Peixe Rey. (Atherinidce, Giinther, Cat., in, 

 391-409, 1861.) 



a Premaxillaries freely protractile, the skin not continuous with that of the forehead. 



6. Premaxillary narrow posteriorly, its edge nearly straight. Body little compressed, the * 

 belly rounded; pectorals short; scales cycloid; vomer with teeth; first dorsal with 

 5 to 9 spines, inserted in front of the rather short anal; mouth short. 



ATHERINA, 352. 



