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no furrow at all. In one female however 1 have seen an indi- 

 stinct furrow in the immoveable finger. 



The other four pairs of walking feet are only partly 

 preserved, having almost always projected beyond the concre- 

 tions wherein the crabs are found, and have therefore dis- 

 appeared. They seem to have been comparatively strong, and 

 rather flat. 



The abdomen consists of seven segments. It is of a 

 longish-triangular form in the males, more oval in the females. 

 In the males the second segment is the broadest, while the 

 greatest breadth in the females is not reached till the third or 

 fourth segment; whether this rule may be considered universal I 

 am not able to determine with perfect certainty, however it is 

 valid with regard to the specimens whose abdomens are 

 completely preserved. The length of the two last segments is 

 greater than their breadth. In the middle of the abdomen an 

 indistinct, broad, longitudinal keel is seen in most specimens. 



Only in rare cases can the nature of the surface be 

 examined, as the shell generally adheres to the stone by its 

 surface, and where this is not the case it is much decayed. 

 Still one sees that it is finely granulated. The granules 

 are generally stronger on the more elevated parts of the 

 shell. 



It has already been mentioned that a row of regular little 

 nodes are found here and there on the border of the carapace. 

 In the Greenland species we also find (in casts or decayed 

 shells) marks similar to those which Noetling has declared 

 to be the places where the muscles were joined to the 

 shell. Such marks are found in the shape of short flat 

 curves at the border between the meso- and metagastric lobes, 

 and in the side furrows somewhat behind the latter two, and 

 moreover in the flat furrow between the mesobranchial lobes 

 and the keels on the metabranchial lobes. 



