Nov, 1768 MARINE ANIMALS 21 
flashes of light coming from it, perfectly resembling small 
flashes of lightning, and these so frequent that sometimes 
eight or ten were visible at the same moment; the seamen 
were divided in their accounts, some assuring us that it pro- 
ceeded from fish, who made the light by agitating the salt 
water, as they called it, in their darting at their prey; while 
others said that they had often seen them to be nothing 
more than blubbers (Medusw). This made us very eager to 
procure some of them, which at last we did by the help of the 
landing-net ; they proved to be a species of Medusa, which 
when brought on board appeared like metal violently heated, 
emitting a white light. On the surface of this animal was 
fixed a small Lepas of exactly the same colour and almost 
transparent, not unlike thin starch in which a small quantity 
of blue is dissolved. In taking these animals three or four 
species of crabs were also obtained, of which one very small 
kind gave fully as much light as a glow-worm in England, 
though the creature was not so large by nine-tenths. Indeed, 
the sea this night seemed to abound with light in an unusual 
manner, as if every inhabitant of it furnished its share; as 
might have been the case, although none retained that pro- 
perty after being brought out of the water except the two 
above mentioned. 
30th. Employed in examining the things caught last 
night, which being taken by the light of our lamps (for the 
wind which blows in at the windows always open will not 
suffer us to burn candles) we could hardly then distinguish 
into genera, much less into species. We had the good 
fortune to find that they were all quite new, and named 
them Medusa pellucens, Lepas pellucens, Clio, Cancer fulgens, 
and Cancer amplectens, but we had the misfortune to lose 
two more species of crabs through the glass in which they 
were contained falling overboard. Two other species of 
crabs were taken, one of which was very singular. 
31st. Find that the crabs taken yesterday were both 
new; called them vitreus and crassicornis. 
5th November. That the trade blows toward the northward 
upon the coast of Brazil has been observed long ago, although 
