STALK-EYED CRUSTACEA 



Section 2. Sesarmini. 



Scsarmini 

 Sesannincc 



Miers, Kingsley. 

 Dana. 



The third and fourth joint of the external maxilHpedes 

 arc crossed by a piHferous ridge. 



Sesarma. 



Synopsis of the Genera. 



A. The fourth joint of the external maxilHpedes is 

 elongate ; its apex is rounded. The external antennae are 

 not excluded from the orbits. 



a. Carapace subquadrate ; sides arcu- qy: '~^ — 

 ate. ^- 



8. Joints of walking feet without 

 spines. — {Sarmatiujn.') 



b. Carapace quadrate. 



9. Sides of carapace straight. — {^Ses- 

 arma). 



c. Carapace elongated. 



10. Carapace narrowed behind. — {Aratus^j 



B. The fourth joint of the external 

 maxilHpedes is short ; its distal border trun- 

 cate or excavated. 



d. External antenna; entering the orbit. 



11. Sides of carapace bowed and entire. 

 grapsus). 



iCyclo- 



A. The fourth joint of external maxilHpedes elongated ; 

 its apex rounded. The external antenncB are not excluded 

 from the orbits : — 



