20 A HISTORY OF RECENT CRUSTACEA 
found a cumacean as low down as 2,050 fathoms, but some 
years earlier the Swedish Spitzbergen expedition obtained 
the appropriately named Diastylis stygia from the still lower 
deep of 2,600 fathoms. The Jsopoda extend down to 2,740 
fathoms, the Amphipcoda possibly, but by no means cer- 
tainly, to 2,500. Among the Entomostracans, a Phyllo- 
carid species came from 2,550 fathoms, Ostracoda from 
2,750, the strange copepod, Pontostratidtes abyssicéla, 
Brady, from 2,200, and a parasitic copepod, Lernwa abys- 
sicola, was attached to a deep-sea fish brought by the trawl 
from 2,400 fathoms. Lastly, of the Cirripedes the great 
Scalpellum regium was dredged from a depth of 2,800 
fathoms, the character of these animals giving more cer- 
tainty than can be had with free-swimming Crustacea, 
that the specimens actually came from the depth assigned. 
In the use of trawls and dredges with open mouths, there 
is always a chance that specimens may be captured in the 
course 9f lowering or hauling in the instrument, instead of 
while it is being dragged along the ocean floor. By this 
means the record of the occurrence of specimens at as- 
tonishing depths is left open to some question. Yet on 
the whole there is fair reason to believe that most of the 
principal groups of Crustacea have representatives capable 
of supporting existence in regions of dense gloom, with 
a temperature icily cold, and under a column of water 
from two to three miles in height. Many species, indeed, 
of the Crustacea show a preference for a frigid climate, 
since where this condition prevails their swarms are far 
vaster and their bodies more bulky and solid than in 
waters less cold. These Polar forms, therefore, find no 
inconvenience, but the reverse, in the unheated tempera- 
ture of the great depths, and though probably many of 
them could not possibly pass the tropical waters at or near 
the surface, far down there is a suitable water-way for 
them from one pole of the earth to the other. 
Tt is rather the task of national expeditions than of 
any private collector to procure the exceptional forms 
which the remotest abysses of the sea have yielded and 
may be expected still from time to time to yield. There 
