14. A HISTORY OF RECENT CRUSTACEA 
any stint of numbers. Less commonly the innocent well- 
shrimps, which are also amphipod crustaceans, may be 
obtained from wells. It may be proper to mention that 
the well-shrimp is not poisonous, and that it flourishes in 
water which is perfectly wholesome. <A different view of 
its character is probably entertained by many owners of 
wells, who are on that account unwilling to mention or 
acknowledge its presence. From stagnant ponds various 
species of Entomostraca may be obtained in vast abund- 
ance. Some of the Phyllopoda are found only in brine 
pools. The brine shrimp, Artemia, breeds in vast num- 
bers in the mud of the great Salt Lake of Utah. In 
South America one of the Ostraccda very singularly dwells 
on the leaves of a plant. The river crayfish and crusta- 
ceans parasitic on freshwater fish are pretty widely dis- 
tributed. Highest in known range of all the Crustacea 
are the Isopods and Amphipods taken by Mr. Whymper at 
a height of 13,300 feet on the Great Andes of the Equator. 
In many parts of the world there are land-crabs, but none 
of these live in the British Isles. This is referred to as 
follows in the ‘ Narrative of the Cruise of the Challenger.’ 
In describing the visit to Ascension Island in the South 
Atlantic Ocean, the writer says :— 
‘Land-crabs swarm all over this barren and parched 
voleanic islet. They go down to the sea in the breeding 
season; they climb up to the top of Green Mountain, and 
the larger ones steal the young rabbits from their holes 
and devour them. It always seems strange to an English 
naturalist to see crabs walking about at their ease high up 
in the mountains, although the occurrence is common 
- enough and not confined to the tropics. In Japan a crab 
is to be met with walking about on the mountain high 
roads far inland, at a height of several thousand feet, as 
much at home there as a beetle or a spider, and crabs of 
the same genus (Jhelphusa) live inland on the borders of 
streams in Greece and Italy.’ 
France and Germany, as well as England, have reason 
to regret that the sunny south should have a monopoly of 
these land or river crabs, for they are delicate eating, and, 
