DOG-CRAB AND FROG-CRAB 143 
of his Cancer raniformis, though in the next preceding 
description he tells of a swift-running ‘ dog-crab,’ Cancer 
caninus, which is said to burrow under houses and enter 
them. When the limbs of Ranina are drawn together it is 
said to look not unlike a frog, a resemblance to which the 
generic name points, as well as the trivial name of frog- 
crab, and the specific name raniformis given it by 
Rumphius. 
Rtaninoides, Milne-Edwards, 1837, is nearly allied to 
Ranina, but has the last pair of legs very short and thread- 
like instead of equal in size and similar in shape to the 
preceding flattened pair. In Raninoides personatus, Hen- 
derson, the pterygostomian areas are described as being 
strongly granulated as well as slightly pubescent, and the 
same is said of the type species of a new genus, Notopoides 
latus, Henderson, 1888. In the female of this species 
there is an ovoid median opening in the sternum, between 
the third and fourth pairs of legs. Raninoides personatus 
has a similar opening but of very small size. The function 
of these apertures does not appear to have been ex- 
plained. 
Notépus, de Haan, 1841, includes several species, in 
which the last pair of legs are of moderate size, not fili- 
form. As the name of the genus implies, their position 
is dorsal, and this, though a character common to the 
family, is again emphasised in the specific name of Notopus 
dorsipes (Fabricius). Of a crustacean allied to this, 
Darwin, in his ‘ Naturalist’s Voyage,’ gives the following 
account :—‘ During our different passages,’ he says, ‘ south 
of the Plata, I often towed astern a net made of bunting, 
and thus caught many curious animals. Of Crustacea 
there were many strange and undescribed genera. One, 
which in some respects is allied to the Notopods (or those 
crabs which have their posterior legs placed almost on 
their backs, for the purpose of adhering to the under side 
of rocks), is very remarkable from the structure of its 
hind pair of legs. The penultimate joint, instead of ter- 
minating in a simple claw, ends in three bristle-like 
appendages of dissimilar lengths—the longer equalling 
