Ifotes on iSortli American Crustacea. 231 



shore. On establishing the name Geograpsus for the group 

 (Proc. Acad. ISTat. Sci. Philad. April, 1858), our impression 

 was that they were terrestrial in their habits, as the only 

 species we had observed living {G. ruMdus) was found in 

 ravines nearly a mile from the sea. But from what we hear 

 of G. lividuSf we now infer that either the habits of the differ- 

 ent species differ, or that they visit the land only at certain 

 periods of the year, — perhaps at the breeding season. 



An additional character for the genus is found in the non- 

 excavated fingers of the large chelipeds. 



]¥aiitilo^rap!$us iiiiniitns. 



Nautilograpsus minutus M. Edw., Hist. Nat, des Crust, ii. 90. 



Found at Cape St. Lucas, by Mr. Xantus. We are unable 

 to distinguish the specimens from those collected from Gulf- 

 weed in the North Atlantic. 



Pla^usia orientalis. 



Plagusia squamosa M. Edw., Mel. Carcin. p. 144. 

 Plagusia orientalis Stm., Proc. Acad. Nat. Sci. Philad., April, 1858. 

 Prodromus etc. p. 49. 



We have received from Mr. Xantus several specimens of a 

 Plagusia from Cape St. Lucas, which we cannot distinguish 

 from the common E. Indian species usually called P. squamosa, 

 but which is not the true Cancer squamosus of Herbst, as may 

 be seen from his figure. It is distinguished from the Atlantic 

 species by the non-dentate superior lobe of the ischium-joint in 

 the ambulatory feet, and by the septem-dentate margin of the 

 epistome. 



APRIL, I860. IQ Aira. Lto. Nat. Hist. Vol. VII. 



