THE FISHES OF NEW JERSEY. 227 



Genus Apeltes De Kay. 



The Three Spined Sticklebacks. 



Apeltes quadracus (Mitchill). 

 Plate 20, 



Stickleback. • Three Spined Stickleback. 



Head 3?^; depth 41^; D. HI-I, 11; A. I, 8; dorsal spine 

 2j^ in head;, pectoral 17^; ventral spine 2; length of caudal 

 peduncle i^ ; snout 3^ in head; eye 3^ ; maxillary 3^4 ; inter- 

 orbital space 3^. Body elongate, compressed, and back elevated 

 at beginning of rayed dorsal. Caudal peduncle very slender, 

 long and not keeled. Head compressed and pointed. Snout 

 compressed and pointed. Eye circular, anterior. Mouth little 

 inclined, and mandible projecting a little. Teeth slender, uni- 

 serial. Maxillary not reaching orbit. Interorbital space narrov^^ 

 and a trifle concave. Gill-membranes attached to isthmus, with- 

 out free edge. Gill-rakers short and sparse. Skin naked. Chest 

 mostly bony. Bare area in front of pectorals small but distinct. 

 Innominate bones not joined on median line but separated, and 

 forming a bony ridge on each side of abdomen below which 

 strong ventral spines are depressible. Innominate bones also 

 wide apart, area between flat, so that a section of fish would be 

 triangular. Scapula forming a small granulated postopercular 

 plate. First dorsal spine inserted before origin of pectoral, 

 longest and strongest, directed to one side. Next two directed to 

 other side at different angles. Space between first and third 

 spines less than space between third and fourth, and first extend- 

 ing beyond base of third. Origin of rayed dorsal about midway 

 between front rim of orbit and base of caudal, and anterior rays 

 elevated. Anal begins a little behind origin of rayed dorsal, and 

 similar. Caudal long and narrow. Pectoral not extending to tip 

 of pubic bone though a little more than half way to anal. Ven- 

 tral inserted just before base of second dorsal spine, also a trifle 

 less than tip of pubic bone, spine strong subterete, serrate on 



