INTRODUCTION. hii 
western shores of Europe. The genus Nenia, all the 
species of which are closely allied in form, has only been 
recorded from the British shores. Four species of Cyr- 
tophium have been discovered, one of which is from the 
East Indies, one from Rio Janeiro, and two from the north- 
west of Europe. Corophium, so abundant when found, 
has been taken on the western shores of Europe, the 
Mediterranean, on the coasts of Japan and Brazil. It 
burrows in mud; but there is reason to doubt either that 
it preys on the Annelids or migrates at particular seasons. 
That terrible wood-destroyer, Chelura, so devastating to 
the piles and submarine timber all round the shores of 
Europe, has not been recorded from other lands. 
We have generally looked upon the Hyperina as pelagic 
species; but recently it has been pointed out by Mr. 
Edward, that some of our British genera burrow into and 
hide themselves in sand on the shores of the Moray Firth. 
The two British species of Hyperia (which we have great 
reason to believe to be but one, being male and female), 
have an extensive geographical range, from Greenland to 
Cape Horn, from Rio to the Zooloo seas. 
Vibiia has apparently an equally extensive range, 
though fewer species have been determined. Themisto, 
also, has been recorded from Greenland to sixty-three 
degrees south latitude in the Atlantic Ocean, while species 
of Phronima have been taken as far north as the Shet- 
lands, as well as in the Atlantic, at Naples, and at 
Borneo. The Caprellide appear to be very universally 
and abundantly diffused. The very close resemblance 
of the species from very distant and opposite localities 
is suggestive of a close affinity in the respective forms. 
Specimens from Japan, and the eastern coast of North 
America, are not appreciably distinct from others found 
on the eastern coast of South America, as well as on our 
English coast ; and when we take into consideration the 
