12 ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 
Cotour.—The specimen above described appears, in its present state, greyish brown, with zig-zag 
lines in different directions of a darker tint. A second individual is stated by Mr. Darwin to 
have been, when alive, “ above salmon-coloured.” A third is described as “ above aureous- 
coppery, with wave-like lines of dark brown, which often collect into four or five transverse 
bands ; fins lead-colour ; beneath obscure ; pupil dark blue.” Both these last specimens appear 
now, like the first, greyish-brown. The wave-like lines extend over a portion of the dorsal and 
anal fins. é 
Habitat, coast of Northern Patagonia, and the mouth of the Plata. 
This species is evidently very closely allied to the P. Brasilianum of Cuvier 
and Valenciennes, and possibly may not be distinct. It differs, however, in having 
only two, instead of three, teeth on the basal margin of the preopercle, which 
character prevails in all the specimens. It has also one or two more soft rays in 
the anal. It likewise approaches the P. aculeatum of the same authors, but this 
last species is said to be particularly characterized by three very sharp points on 
the subopercle towards the lower angle, in the room of which, in the species 
here described, there is only one small triangular flattened point, rather sharp in 
two individuals, but in the third blunt, with the margin slightly crenated. The 
colours too appear to be different. 
Mr. Darwin’s collection contains three specimens, which do not materially 
differ from each other. The largest, measuring fifteen inches in length, was taken 
in forty fathoms water off the mouth of the Rio Plata. The two others, smaller, 
and not exceeding nine, and seven and a half inches respectively, were got on the 
coast of Patagonia in lat. 38° 20': where it is stated that great numbers were 
obtained, many exceeding a foot in length. In these smaller specimens the 
canines are not so numerous or well developed as in the larger one. 
“One specimen when caught, vomited up small fish and a Pilwmnus. Was 
tough for eating, but good.”—D. 
DIAcOPpE MARGINATA. Cuwv. 
Diacope marginata, Cur. et Val. Hist. des Poiss. tom. ii. p. 320. 
Form.—Greatest depth of the body and length of the head equal, each being not quite one-third of the 
entire length. Nape somewhat elevated, whence the profile falls very regularly in a slightly convex 
line. The jaws appear equal when open, but when closed the upper one is a little the longest. 
Teeth velutine, with four well-marked canines in the upper jaw, two on each side of the anterior 
extremity, the outer one of which is longer than the inner. Opercle with two flat blunt points. 
Denticulations of the preopercle, particularly those at the angle below the notch, moderately 
well developed. Tubercle of the interopercle prominent. There are scales on the cheeks and 
pieces of the gill-cover, but none on the crown, snout, jaws, or suborbitals. The scales on the 
