ZOOLOGICAL SOCIETY BULLETIN 
77 
with motion than mentality, and they have re¬ 
mained at a low psychical level.” 
Dr. Carl H. Eigenmann in his spdendid work 
on “The Fresh-water Fishes of British Guiana” 
has recorded three hundred and sixty-two spe¬ 
cies from the Colony. At the Tropical Re¬ 
search Station of the Zoological Society at Kar- 
tabo we have only begun work on the fish fauna, 
but every specimen and note is of interest, for 
Eigenmann omitted from his reconnaissance 
quite one-third of the whole of Guiana,—the 
regions drained by the great rivers of the Maza- 
runi and the Cuyuni, whose waters bound our 
station. 'Without any thorough seining or sys¬ 
tematic netting of the waters, we have notes on 
sixty-five species which occur in or near the 
junction of the rivers in front of the laboratory 
or in the jungle swamps and creeks in the area 
of observation immediately behind. 
While the low mentality of fish is undoubtedly 
a fact, yet this is compensated by the interest 
of their great diversity of form and size, mar¬ 
vellous beauty, and remarkable habits, and per¬ 
haps most of all by their vital suggestions of 
past evolution and the vivid evidence of evolu¬ 
tion going on to-day, which they express in 
their bodies and their life habits. 
As in the jungle, so the tropical waters teem 
with unexpected and strange organisms, and 
there is no level or niche left unexplored or 
unoccupied by one or more species of fish. In 
a brief, introductory article such as this it is 
possible to mention only a few of the many 
interesting aspects of fish life about the station. 
In extremes of size we find schools of little 
Sword-finned Minnows close in shore, measur¬ 
ing less than an inch in length, while farther 
out great lau-lau catfish swim about, brobdig- 
nagian bull-heads six to twelve feet in length, 
with grinning mouths two feet wide. They will 
occasionally take the hook but put up no more 
fight than would a barrel of cement. The larg¬ 
est fresh-water fish in the world and one of 
the most gamey also inhabits Guiana waters, 
the arapaima, which reaches a length of fifteen 
feet and a weight of over four hundred pounds. 
The flesh of all these fish is most delicate. 
Many of the fish are very beautiful, but on 
the whole there is hardly an average of greater 
brilliancy of pigment than in the fishes of tem¬ 
perate waters. Scarlet eels and golden cat¬ 
fish with fins of flame color are rather astonish¬ 
ing when they swim up through the brown 
water; and many-colored ocelli or eyed spots 
are rather common both on fins and bodies. As 
to variety of form there is no end. To take 
mouths alone, there is the elongated tube of the 
pipefish, the swordfish-like needlefish and the 
halfbeak with its minute upper mandible, and 
enormously lengthened under jaw. Most fright¬ 
ful looking fish come up in the seine, such as 
the silvery biara or dog-toothed fish with teeth 
so long that they pass clear through the head 
and project into the water above, yet which 
is a fish wholly innocuous; on the other hand 
a meek appearing sunfish is in reality the notori¬ 
ous Perai, one of the most dangerous of all 
fishes. Nothing more hopeless can be imagined 
than to be attacked by a school of these razor- 
toothed little fiends. 
The sand gobies, when frightened, flatten 
out on the bottom, and draw over themselves a 
mantle of color identical with that of their 
background; the comical green and black- 
banded puffers, au contraire, distend themselves 
with air into a taut, skinny, inedible ball, and 
float out of reach upon the surface until danger 
is past. 
The fish about Kartabo show three important 
radiations: first, intrusions from the salt water 
of the open sea, fifty miles away by water line; 
second, aerial attempts, and third, terrestrial 
trials. As unexpected intrusions from the sea 
we find the Gobies,—the commonest species 
hereabouts being as yet undescribed; the young 
gar or needlefish are also essentially marine. 
Most remarkable are the sting rays, two species 
of which have deserted salt water and inhabit 
our rivers. The last oeellated ray which we 
caught on a set line, gave birth to five young 
rays in the boat; in an aquarium the little rays 
flapped slowly about on the sand and the back 
of the mother. 
The four-eyed fish is also essentially a lover 
of salt or brackish water but occasionally it 
enters the fresh waters about Kartabo. It is, 
however, as an invader of the air that it holds 
greatest interest, the upper part of the eyes 
being modified for atmospheric vision, while it 
appears unable to remain more than a foot or 
two beneath the surface. The second aerial 
aspirant is the fresh-water flying fish, built 
rather on the lines and method of operation of 
a hydroplane than an airplane, as it rises with 
a rush and slithers along the surface, its deep 
keel usually cutting a tiny furrow as it goes. 
The piscine land invaders are of extreme in¬ 
terest, both on account of their individual spe¬ 
cializations and their evolutionary significance. 
If a pool forms after aj^eawy'-ram^deep within 
the jungle, or on .a .hillside’ wells, away from 
water, it may soon contain fish as weil.-as' tad¬ 
poles and whirligig beetles; fish not descended 
with the rains, which have scrainbledwajnd 
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