76 GENUS LIBINIA. 



licial characters it seems to claim proximity to tiie genus 

 Grapsus, notwithstanding its diverse mode of life. 



These considerations and comparisons have induced 

 me to indicate the characters partially, of a new genus for 

 this animal, under the name of Sesarma (from o-uipa the 

 act of gaping,) this genus of course can be adopted or re- 

 jected, by those who have an opportunity to examine a 

 more numerous list of species of its neighbouring genera^ 

 than I can obtain access to. 



Genus SESARMA. 



Antennae short, inserted in a right line between the eyes, 

 under the clypeus; seta of the interior ones shorter than the 

 preceding joint; second joint of the peduncle of the exter- 

 nal pedipalpi, oval, as large as the first, and forming an angle 

 with it on the inner edge; palpi attached to the outer tip, 

 first joint compressed, rather longest, second and third near- 

 ly equal, not reaching the base of the second joint of the pe- 

 duncle; body somewhat cubical; arms equal; no oblique la- 

 teral line, or prominent dense hair between the third and 

 fourth hips; tarsi simple, conic, acute. 



Genus LIBINIA. Leach. 



Ma J A. Pabr. and Latr. 



Thorax rounded, spinose, with dense hair; rostrum 

 entirei eyes hardly thicker than their ped uncles • orbit with 

 a fissure above and one beneath exterior antennce as long 

 as the rostrum, the first joint longer than the second, the 

 third slender: external double pedipalpi with the second 

 joint of their internal peduncle, abruptly and deeply euiar- 

 ginate, for the insertion of the palpi, and with its interior 



