FORM AND FINS 
face is accurately rounded, 
and there appear no irregu- 
lar points which could re- 
tard the forward motion of 
the fish, Even in the 
wedge-shaped head the 
conical surface has been 
made more perfect by the 
tightly fitting rims of the 
jaws, by the smoothly 
. closed gill shields, and by 
the eyes’ accurate adjust- 
ment to the head’s curva- 
ture. Viewed from in front 
(Fig. 4) the fish’s outline 
appears as a perfect ellipse, 
and seems. surprisingly 
small in size : the fins, which 
appear so prominent a feat- 
ure in profile, can now 
be hardly distinguished ; 
above and below they form 
keels, sharp and thin. In 
side view the vertical or 
unpaired fins are seen sur- 
rounding the hinder region 
of the body: they resolve 
themselves into dorsal (D), 
anal (A), and caudal (C) 
elements; the former are 
low and stout, elastic in 
their firm cutwater margin, 
deeply notched and inter- 
Fig. 3. — Type of swift swimming fish, 
Spanish mackerel, Scomberomorus macula- 
tus (Mitch.), J. &G. x 3. (After GOODE 
in U.S. F.C.) 
