ORDER DECAPODA. 
147 
This family might, as in many methods anterior to the 
distribution of these animals by Daldorf, form but a single 
genus, that of 
Crab, (Cancer.) 
The greatest number have the feet all attached to the sides 
of the breast, and always exposed. The first five sections 
are in this predicament. The first, or the Swimmers (Pin- 
NIPEDES) unites to this character, that of having the final 
feet at least terminated by a very flatted articulation like a 
fin, (oval or orbicular, and broader than the same articulation 
of the preceding feet, even when they also are fin-like.) They 
remove more frequently from the shore, and proceed into the 
high sea. If we except the orithyise, the tail of the males 
presents but five distinctly marked segments, while that of 
the females has seven. We shall commence with those, all 
of whose feet, the claws excepted, are natatory. 
Matuta, Fab., 
Have the testa almost orbicular, and armed on each side with 
a very strong tooth in the form of a spine. The hands are 
denticulated above, in the manner of a ridge, and bristling at 
their external face, with pointed tubercles ; and the third 
articulation of the external jaw-feet is without any apparent 
notch, and terminates in a point, so that it forms, with the 
preceding articulation, an elongated and almost rectangular 
triangle. The external antennae are very small. The ocular 
pedicles are a little arched. Cancer latipes , Degeer. 
Polybius, Leach . 
Approximate to the Portuni ; but their testa is proportionably 
less broad, and more rounded. Its sides only present the 
