19(5 On Fossil Crustacea from New-Jersey. 



The remains in our cabinet consist of fragments only : that 

 is to say, we have parts of eight hands, more or Jess perfect, 

 (four of the right side, three of the left, and one doubtful,) 

 and the third joint of one of the legs. The great dissimilarity 

 of these several parts evinces to me four very distinct varie- 

 ties, which I shall endeavour to describe, in reference to 

 Plate XIV. 



Fig. I. The right hand of a crab viewed internally, where 

 it is flat and smooth ; externally, protuberant. The finger 

 moveable. Thumb and finger of equal length, smooth, 

 slightly compressed internally, and rounded externally. 

 We have the corresponding left hand in a more perfect 

 state as to outline, but with small parts of the finger 

 wanting. 

 Fig. 2. This specimen is unfortunately much fractured. I 

 have presented an external view of the left hand, which has 

 suffered great violence, and has the finger and thumb bro- 

 ken and out of place, but still slightly adhering. The 

 lower margin of the hand is smooth, as is the outer margin 

 of the finger ; the thumb, on the contrary, has a double 

 row of small spines accompanying its lower margin. 

 Fig. 3. Represents the interior of another left hand, on 

 which only small parts of the thumb and finger are visible. 

 The exterior is beautifully circular, the interior ovate and 

 emarginate. In Hip r.pntral line are several small spines or 

 tubercles, which are again observed more thickly surround- 

 ing the root of the thumb, and extending along its upper 

 margin. Part of this thumb has been accidentally broken 

 off since we found it. We possess also a right hand, about 

 as perfect as this, which, from its position when found, and 

 the strong resemblance, I take to be its fellow ; it certainly 

 belonged to an animal of the same species. 

 Fig. 4. Part of a claw, with the greater part of the thumb 

 and finger. The claw is compressed and emarginate. 

 The smaller finger is an irregular triangle, bearing spines 



