4»« 



PALiEONTOLOGY OF NEW- YORK. 



Fig. 5 : Eurrpterus lacustris. 



FlO. 5. A fifrure of the restored parts of Eurypterua lacustris, 

 showinf; the lower surface of the car;ipacc, the first four articula- 

 tions of the body, the feet, etc. 



C, tbecmrapcee; M, the mouth; r, the poat-oral plate. 



■>, m, the base* of the finst jointa of the feet, all or a part of which perform 

 the functioDH of jnwH. 



r, r, the flattened Hpaeei* ^hich are covered by the next succeeding member 

 when the partJ arc in their natural poiiitiun. 

 The feet on the right side of the figure are numbered 1, 2, 3, 4 and 5, 

 Eorrespooding to the orders of the pairs of appendages. 



On the left side of the figure, one of the third pair is numbered correspond- 

 ing to what appear to be the number of articulations. If we leave out the 

 third Joint, which may be only an apparent articulation, and the terminal 

 spine, we have seven joints in this and the other feet. 



The swimming foot on the left side of the figure is similarly numbered. 

 The fig. 7j has reference to the fixed ramus of the chela; i.b, the suture by 

 which this is joined to the posterior portion of the joint. 



In the articulations of the body, the figures 1, 2, 3 and 4 hare reference 

 to the number of the segments in their order. The letters indicating the parts 

 of the locomotive appendage have already been explained on a previous page. 



