the Trondhjem Fiord. 345 
The Crustacea of the Norwegian fiords possess a peculiar 
interest when compared with British and Aretic species. As 
we go further and further north the Brachyura and Anomura 
gradually decrease in number, and species after species drops 
out. To make up for their absence there is a much lar eer 
development of Cumacea, Mysidea, and Amphipoda on the 
Norwegian coast, while in the true arctic seas the Amphipoda 
attain their maximum development—not, as far as yet known, 
perhaps in namber of species, but in size and multitude of 
specimens. The following list will give evidence of this 
gradual suppression of Brachyura and Anomara :— 
Brachyura. Anomuraf. 
Mediterranean: * : .42), 50.2 ese: 3 iene Ue 23 
EERIE Hee ee, oro narelaes ouate aie sineeel ee oe 49 15 
ISIGIA CA ie See ae See Gr Oe et ne ae ea 24 S) 
Greenland, Spitsbergen, and Kara Sea., 3 2 
Of the three Arctic Brachyura the great Chionwcetes pha- 
langium is a truly arctic form, caronninles in its distribution. 
It often measures 24 feet in stretch of legs. It rarely occurs 
outside the Arctic Cia. but on the American coast has been 
found as far south as Casco Bay (S. ZL. Smith). On the 
coast of Europe itis unknown. yas araneus and co urctatus 
grow to an immense size in Greenland, but occur southwards 
to the south coast of E ngland in oreatly dwarfed dimensions. 
The two Anomura, Lithodes arctica and Eupagurus pubescens, 
also reach England. If we deduct these four species it is 
very remarkable that of the remaining twenty-nine species of 
Norwegian Brachyura and Anomura there is only one, and 
that of very small size, Hupagurus chiroacanthus, Lillj., which 
is not as yet known in the Mediterranean. Corresponding to 
the decrease in the number of higher Crustacea as we go 
northwards is the similar falling off in numbers as we descend 
to greater depths in the seat. Macrura, on the other hand, 
are nal unequally distributed, but seem to occur in no oreat 
disparity of numbers in arctic, temperate, and warmer mer 
and in the great depths of the ocean. 
The most marked peculiarity | of the Norwegian fiords with 
Bape to the class Crustacea is the abundance of Mysidea 
and Cumacea. In the month on the Trondhjem Fiord I 
obtained more specimens of this. tribe than I have found 
* T have not counted a great many doubtful species recorded from the 
Mediterranean in Carus, ‘ Faune Medit. Prodromus.’ 
+ [have not here mchaded the family Galatheidee in the Anomura. 
No species of that family is found in the Arctic regions. 
{ See Norman, “ Presidential Address,” Trans. Nat. Hist. Soe. and 
Tynes. Nat. Field Club, vol. vill. (1883), p. 108. 
