142 A HISTORY OF RECENT CRUSTACEA 
legs. In Dorippe, Leucosia, and Ranina, the lower border 
of the trunk closely coheres with the epimera (compare 
Milne-Edwards, vol. 2, p. 193). In the first the anterior 
apertures, in which the first joints of the third maxillipeds 
work, are remote from the base of the chelipeds; but in 
the following they are altogether wanting; so that these 
have only one path on each side by which the water reaches 
the branchiz, and one by which it is withdrawn. The 
hinder ducts in Ranina are broader than in other families 
and amplified by lateral apophyses, but otherwise in Portu- 
nus and Grapsus they are in the same place. The water 
appears to enter the branchial cavity by the anterior aper- 
tures, and to issue by the hinder ones, and not to have a 
diverse or in ftanina and Leucosia a contrary motion 
(compare Milne-Edwards, vol. 1, p. 88, vol. 2, p. 194). 
In the anterior part there is a force, namely the movement 
of the maxillipeds, by which the water is brought in ; that 
being expelled behind, follows the movements of the body ; 
the apertures beside the base of the chelipeds and the 
branchial appendages of the maxillipeds are ciliated on 
the margin, and by these cilia alien bodies are kept away 
from the branchiz, when water is brought to them from 
in front, whereas [they would be] of no use but a hindrance 
to breathing, were the water brought from behind.’ 
Fritz Miiller refers to the statement made by Milne- 
Edwards about the breathing arrangements of Ranina, but 
does not mention de Haan’s contrary opinion. Fritz Muller 
himself unfortunately had not had an opportunity of per- 
sonally investigating the question Judging from Milne- 
Edwards’ figure of Ranina dentata, it would appear to 
have an arrangement of the pterygostomian regions not 
unlike that already described in the genus Sesarma, by 
which the crab when on dry land is enabled for a long 
time to go on breathing the same small stock of sea-water. 
Such an arrangement would undoubtedly be convenient 
for the Ranina, if the story be true that it has a decided 
propensity for climbing on to the roofs of houses. Milne- 
Edwards attributes this story to Rumphius, but nothing 
of the kind appears to be included in that author’s account 
