FISH. 25 
Eyes large ; their diameter more than one-fourth that of the head. Suborbitals marked on their 
surface near the lower margin with six or eight diverging salient lines, each terminating at 
bottom in a mucous pore. Teeth forming a narrow velutine band, hardly visible to the naked 
eye, but sensible to the touch: none on the vomer or palatines. Opercle with one short flat 
spine projecting beyond the posterior margin rather more than half a line. Barbules reaching 
to a little beyond the angle of the preopercle. Mucous tubes of the lateral line with five or six 
branches; the branches not always simple,* but consisting sometimes of two or three main ones 
which are subdivided. First dorsal of a triangular form, with the spines rather slender; the 
first two equalling more than three-fourths of the depth of the body. Space between the dorsals 
about equalling the length of the first. Second dorsal with the first ray (or spine) scarcely 
more than half the length of the second, which is longest; the third and succeeding rays gra- 
dually decreasing to the last, which is shortest. Length of the second dorsal just equalling its 
greatest height. Anal answering to this last fin. Caudal deeply forked; the central rays not 
being one-fourth the length of the outermost ones. Ventrals and pectorals exactly of the same 
length; both reaching to a vertical line from the extremity of the first dorsal. Vent in a line 
with the commencement of the second dorsal. 
D718 A. 6.Os 15, &er Ps 165) Vn 1/5: 
Length 6 inches 9 lines. 
Cotour.—“ Dull silvery, with a yellow stripe on the side.” —D. 
There can be but little doubt of this species being the U. flavolineatus, which 
appears to have a wide range over the Indian Ocean, and also to occur in the 
South Pacific. Mr. Darwin’s specimen was taken at the Keeling Islands. 
2. Ureneus trirasciatus. Cuv. et Val. 
Upeneus trifasciatus, Cuv. et Val. Hist. des Poiss. tom. iii. p. 344. 
Form.—General form resembling that of the Mullus Surmuletus, but the snout more elongated. 
Greatest depth contained about four times and a half in the entire length. Head exactly one- 
fourth of the same. Eyes small, distant three diameters from the end of the snout. Suborbitals 
with a moderate number of pores on their disk, but without any salient lines. Posterior extre- 
mity of the maxillary broad. A single row of conical teeth in each jaw, very uniform in size, 
not very large or very close ; about twenty-two above and twenty below. Spine of the opercle 
about a line in length. Barbules reaching to, or a little beyond, the posterior margin of the 
opercle. Lateral line not much ramified. Height of the first dorsal equalling more than half 
the depth. Space between the two dorsals equalling one-third the length of the second dorsal. 
* As stated by Cuvier and Valenciennes. 
E 
