132 ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 
the adipose, or perhaps a trifle beyond it; two small spines at its commencement ; the first two 
soft rays simple, the others branched. Caudal forked for half its length, the lobes equal ; the whole 
fin contained about six and a half times in the entire length; the accessory rays very numerous, 
and partially fringing the upper and lower edges of the tail. Pectorals attached behind the 
gill-opening, rather below the middle, about two-thirds the length of the head, of a somewhat 
triangular form, the rays gradually shortening from the first, which is the only one unbranched. 
Ventrals attached a very little in advance of the dorsal, rounded, or almost eut square at the 
ends, the rays being all nearly equal. They are scarcely shorter than the pectorals: the space 
between their insertion and the commencement of the anal is nearly double their own length. 
There is no long scale or appendage of any kind in their axille. 
Cotour.—* Dull leaden colour.”—D.—In spirits it appears brown. The sides are banded with 
some irregular transverse zebra-like marks, not noticed by Mr. Darwin, reaching from the 
back down two-thirds or three-fourths of the depth, some terminating sooner than others. All 
the fins brownish. 
Habitat, Falkland Islands. 
Mr. Darwin obtained three specimens of this remarkable fish all precisely 
similar, from a fresh-water lake in the Falkland Islands, in March. The lake 
was not far from the sea, and connected with it by a brook. He adds in his notes 
that the species is common there; that it is good eating, and grows to be about 
half as large again as the individuals procured. 
One of these specimens was dissected by Mr. Yarrell and myself, and pre- 
sented the following internal characters, which are of importance to be noted. 
The coats of the stomach were thick and muscular; the cesophageal portion with 
prominent longitudinal plice. Its contents, so far as they could be ascertained, 
consisted of the remains of caddis-worms. The intestine was large, without any 
coecal appendages, but with one spiral convolution at the end of the first third of 
its length from the pyloric orifice : the entire length of the canal was four inches. 
The air-bladder was large, undivided, and of the same general form as in many 
of the Salmonide. There were two elongated flattened lobes of roe nearly ready 
for exclusion. The anal and sexual orifices were separated, but enclosed ina 
tubular sheath, common to both, directed backwards; the sheath itself lying in a 
groove in the abdomen, and five-eighths of an inch in length: the opening to the 
cavity of the abdomen and sexual organs was at the extreme end of this sheath, 
and partly closed by two lateral valves ; the opening to the intestine, three-eighths 
of an inch short of the extremity. 
2. APLOCHITON TENIATUS. Jen. 
Puate XXIV. Fic. 2. 
A. olivaceus, punctis fuscis minutissimis irroratus; lateribus vitté longitudinali ar- 
gented: maxilla inferiore longiore. 
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