18 A HISTORY OF RECENT CRUSTACEA 
live on tand or in shallow waters, or on the coast, and of 
those specimens which are brought to shore either as or in 
connection with articles of food, the student may obtain a 
thoroughly representative collection. Closely as all the 
easily accessible localities and resources have been already 
searched and examined, even from among them he will 
find it still possible to add new species to the long roll of 
those hitherto known. In many of the forms that are 
common and abundant, and that have long been familiar 
to science, he may, by diligent observation, find features 
of great interest that have heretofore escaped notice. One 
discovery he will almost certainly make, that the objects 
of his study do not deserve the epithets of contempt and 
disgust so freely lavished upon them by the ignorant. At 
every step he will be increasingly charmed by the striking 
characters which different species exhibit, by the delicate 
grace or the intricate mechanism of the separate parts, and 
by the marvellously varied adaptation of the different or- 
ganisms to their diverse modes of life. 
It is, however, in the waters of the ocean, from the 
surface down to the abyssal depths, that the vast majority 
of the Crustacea are to be found. Of the lower limits of 
the so-called bathymetrical distribution a good general 
idea may be formed from the results of the dredging and 
trawling carried on by the Challenger, during a voyage 
of nearly seventy thousand miles. Of the Brachyura 
indeed, only a single specimen of a single species was 
taken so low down as 1,875 fathoms. Mr. Miers, who 
named it Hthusa (Hthusina) challengeri, says: ‘This is the 
greatest depth at which any Brachyurous crustacean was 
taken by the expedition, and also, I believe, the greatest 
hitherto recorded for any species of crab.’ It was not, 
perhaps, to be expected that members of the highest order 
in the class would either need or condescend to penetrate 
into the very lowest regions, where light and heat and 
vegetation, not to speak of cheerful society, must at the 
best be very scanty and extremely scarce. The very genus 
Hthusa, with its sub-genus or neighbouring genus Hthu- 
sina, seems to apologise for frequenting levels beneath its 
