On Fossil Crustacea from New- Jersey. 107 



on the angles. The thumb or longer finger has five rows 

 of spines extending its whole length, and approximating 

 towards the smaller extremity. 



It is exceedingly difficult to trace analogies between fossil 

 and recent species, especially where only parts of the animals 

 are offered for observation. Moreover, the old Linnean genus 

 Cancer has undergone so many alterations and modifications 

 by the labours and observations ofFabricius, Bosc, Latreille, 

 and Leach, that it is not easy to arrange recent, much less 

 fossil specimens. I must be allowed to remark, however, that 

 fig. 4. presents many points of resemblance with the Pagurus 

 Faujasii of Desmarest, as exhibited in PI. XI. fig. 2. 

 of his work on Crustacea, in conjunction with M. Brongniart 

 on Trilobites. It strongly resembles the smaller claw on that 

 plate, the original of which was from Maestricht, and describ- 

 ed by Faujas St. Fond as the Pagure Vhermite : and which 

 Latreille notices as approximating very nearly to the Pagurus 

 Bernhardus. The analogy between the recent and fossil is so 

 great, that they might easily be mistaken : the only difference, 

 perhaps, being the length of the claw. A circumstance tend- 

 ing to confirm the supposition of M . Latreille, that it was the 

 hermit crab, is the fact that only claws are found at Maestricht, 

 and never the body, which he accounts for naturally from the 

 durability of the claw, and the liability of the body to de- 

 composition. Although at Tinton Falls we saw many claws, 

 neither of us could discover any other part of the animal. 



Messrs. Cuvier and Latreille place all the fossil Crustacea 

 hitherto found (with the exception of two specimens) in the 

 first order, viz. decapode : so that we are probably correct in 

 the place assigned to our new varieties of fossil. 



The crabs of Maestricht are found in a formation analogous 

 to, perhaps equivalent with, the chalk of England, in which 

 Mantell first noticed them. They are found in the plastic 



