108 
ICHTHYOLOGY 
it by a membrane about as high as it is itself ; the third spine is 
very short and wide apart, being placed from the second at 
a distance equal to the diameter of the orbit ; it is joined to 
the precedent spine by a very low membrane ; the second 
dorsal is rather high, triangular, and formed of twenty-two 
rays ; the caudal is as long as the snout, rounded at its extre- 
mity, formed of twelve rays, several of which are much 
thicker than the others ; anal of the same form as the second 
dorsal, of nineteen rays ; the pectorals are formed of fifteen 
rays; the pelvic bone is covered with very strong irregular 
spinulets, and is ended by a similar ventral spine. 
The colour is of a light yellowish brown, darker on the back ; 
this part presents faint traces of annular spots ; the base of 
the second dorsal has also traces of brown spots, and at the 
base of the anal there are one or two very irregular obscure 
blotches ; on each side there is a very faint brown line, which 
bifurcates itself towards the middle of the body in two 
oblique branches, one running to the posterior edge of the 
dorsal, and the other to the one of the anal ; the fins are of a 
bright yellow. 
My unique specimen is only one and a half inches long, and 
I should have hesitated to establish a species on probably such 
a young fish, if it had not presented so well defined 
characters ; it is probable that the very faint traces of spots 
that it presents change with age. 
The disposition of the dorsal spine is very much like those 
of B. Azureus, Lesson (Voyage de la Coquille, Zool. pi. 10, 
fig. 2) that Dr. Gunther unites with several other sorts, to 
obtain the result he so much seeks for. 
M ON ACANTHUS BRUNNEUS. 
Enters in division characterised by : anal fin with less than 
forty rays ; dorsal spine with only two series of barbs, which 
point backwards ; ventral spine anchylosed to the pelvic 
bone. 
Height contained twice and one-third in the total length ; 
head three times and two-thirds in same ; eye three times in 
length of head ; body rather elongate, covered entirely with 
