THE FISHES OF NEW JERSEY. 
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Genus APELTES De Kay. 
The Three Spined Sticklebacks. 
Apeltes quadracus (Mitchill). 
PLATE 20. 
Stickleback. Three Spined Stickleback. 
Head 3%; depth 4%; D. III-I, 11; A. I, 8; dorsal spine 
22%4 in head; pectoral 1%; ventral spine 2; length of caudal 
peduncle 174; snout 3% in head; eye 3%4; maxillary 334; inter- 
orbital space 324. 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 narrow 
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 
