Dules Auriga, _Cuv. et Val._ Hist. des Poiss. tom. iii. p. 83. pl. 51.
FORM.—This species is remarkable for the prolongation of the third
dorsal spine, which, in the present specimen, is not quite equal to
half the entire length of the head and body; a small portion,
however, appears to have been broken off. The greatest depth is
contained three and a half times in the entire length. The head,
measured to the extremity of the opercular membrane, exactly equals
the depth. The line of the profile is not quite straight, there
being a slight depression at the nape, above which is a convexity in
immediate advance of the dorsal fin. The lower jaw is a very little
the longest. The eyes are large; and the distance between them
barely equals their diameter. The other characters are exactly as
stated in the “Histoire des Poissons.”
B. 6; D. 10/13; A. 3/7; C. 17; P. 17; V. 1/5.
Length 5 inches 3 lines.
COLOUR.—The recent colours are given by Mr. Darwin in his notes as
follows: “Sides with numerous waving longitudinal lines of brownish
red; the intermediate spaces greenish-silvery, so figured as to look
mottled. Head marked with lines of dull red and green. Ventral and
anal fins dark greenish blue.”—He does not notice the vertical bands
alluded to by Cuvier and Valenciennes, which are sufficiently
obvious, and which accord with the figure and description of the
authors just mentioned.
Habitat, Maldonado Bay, Rio Plata.