4. 
t 
# 
A. 
Fishes of Massachusetts. 359 | 
duced by a gradual change, but an entire absence of 
rays, from the eighteenth, which is perfect, to the 
posterior rays, which are also all perfect. 
Yarrell observes, that the edges of the sword are 
“finely denticulated.” In that portion of the edge 
. of the sword before me which is perfect, itis entirely 
smooth; the greater portion of the edge is broken at 
initorsiids — unnaturally, evidently by use. 
x 
Tracuinotus. Lacepede. lc d 
= 
Generic characters. Free spines on the back, 
and two others, also free, before the anal; body ele- 
vated, and the tail without the lateral carine ; pro- 
file vertical; and the dorsal and anal fins peiie 
to points more or less long. 
R argenteus. Cuv. The Rudder Fish. 
Cuv. et Valene. Hist. Nat. des Poiss. t. viii. p. 413. 
Dr. Yale sent me from Holmes Hole, three speci- 
mens of a fish, generally known at the Vineyard by 
the name of “rudder fish," which, after considera- 
S -ble hesitation, I have concluded to be the “ T. ar- 
"E 
abe 4 
E 
genteus," Cuv. The smallest specimen, two inches 
in length, answers perfectly to the figure, in Mitch- 
ell’s “Fishes of New York," incorrectly called by 
him “Coryphena hippurus.” This small specimen 
was taken at a wharf at Holmes Hole. The two 
large specimens were caught about fifteen miles from 
land. Dr. Yale writes me, that “this fish is gen- 
erally found at sea, but is common in our waters. 
