PHARYNGEAL TEETH OF FISHES. 455 
triangles, with the narrow apex at the forward end and the base, 
which is nearly right angled, at the esophagus end. 
DACTYLOPTERID/. 
DactyLopreRus vouitans. The Flying Gurnard. Fig. IIL., c. 
Has eight flat tubercles for gill-rakers along the cerato- 
hypobranchial of the first arch, with two on the epibranchial. 
These are all smooth to the touch. The other arches are 
furnished, as is the inner side of the first arch, with alternating 
tubercles, which yet leave a small opening between them for the 
passage of water. The upper pharyngeal teeth are in two rows 
of distinctly conical teeth in the upper patch, and also similar 
teeth at the lower portion of a circular pad of teeth; between 
these sets of conical teeth are villiform teeth. The lower 
pharyngeal teeth are villiform. 
SCOMBRIDA. 
ScoMBER scomBrus. The Mackerel. 
This fish has twenty-eight very long, horny gill-rakers on the 
first cerato-hypobranchial arch ; the longest one is at the angle 
of the arch, and is about one and a half times the depth of the - 
gill lamina below it. The gill-rakers diminish in size as they 
approach the tongue, but keep fairly long all the way. There 
are thirteen on the first epibranchial. All these gill-rakers, 
although smooth to the touch, have a fringe of small hair-like 
bristles along the inner face, making each one look like a 
miniature spoke-cleaning brush. When looked at collectively 
with a magnifying-glass the whole gives the appearance of a 
closely-set hair-brush. The gill-rakers on the other arches are 
short, but covered with the hair-like bristles, the whole forming 
such a filtering apparatus as to entangle the smallest organisms. 
The upper pharyngeal teeth are on a thin elongated strip on the 
second epibranchial, and a long and fairly broad patch on the 
third and fourth epibranchials; both these are thickly furnished 
with setiform teeth. The lower pharyngeal teeth are set on two 
long narrow plates, and are setiform. 
