Notes on North American Crustacea. 233 



their tops, where they are often found. They run with rapidity 

 and are difficult to secure. 



Oecarciiius [ruricola. 



Gecarcmus ruricola Latr. 



Found at Key Biscayne, by Mr. "Wurdemann, and at Hayti, 

 by Dr. Weinland. The Florida specimen is narrower and more 

 convex than that from Hayti. 



Gecarcinus quadratus. 



Gecarcinus quadratus Sauss., Kev. et Mag. de Zool., 1853, v. 360. pi. 

 xii. f. 2. 



A specimen was found at Cape St. Lucas, by Mr. Xantus. 

 It does not agree exactly with M. de Saussure's description and 

 figure, as the lateral carina of the dactylus of the ambulatory 

 feet is less spinous, approaching in character that of G. lateralis. 

 The meros-joint of the external maxillipeds is short, and entire 

 anteriorly, but not produced forward as in G. ruricola, 



\ Oecarcinus lateralis. 



Gecarcinus lateralis Guerin. 



The terms of Milne Edwards' description of this species are 

 not always strictly correct, for the meros-joint of the external 

 maxillipeds has often a slight notch or concavity on the anterior 

 margin. Also, the dactylus of the ambulatory feet has some- 

 times a few spines on the lateral carinas toward the extremity. 



Found at Key Biscayne, by Mr. Wurdemann, and at the Tor- 

 tugas, by Capt. Wright. 



