STALK-EYED CRUSTACEA 231 



3. Dilocarcinus. 



Dilocarcinus . Rathbun, Ortmann, H. Milne Edwards. 



The carapace is very convex in an antero-posterior 

 direction ; lateral teeth spiniform. The lower margin 

 of the orbit and the ridge at the angle of the buccal 

 cavity are usually armed with spines. Eyes large, not 

 diminishing in size at terminal half. Terminal joint of 

 walking legs narrow, flat, with hairy borders. 



Synopsis of the Species. 



A. Lateral border of carapace has, counting the ex- 

 ternal orbital angle, four teeth. — (D. margavitifrons^ 



B. Lateral border of carapace has, counting the ex- 

 ternal orbital angle, five teeth. — {D. eniarginatus^ 



a. One tooth on external buccal angle. — {D. spini- 

 frons) 



b. Two teeth on external buccal angle. — {D. pictus.) 



C. Lateral border of carapace has, counting the ex- 

 ternal orbital angle, seven teeth. 



c. No teeth on external buccal angle. — {D. castelmani^ 



d. Six teeth on external buccal angle. — (Z?. spinifer.) 



D. Lateral border of carapace has, counting the ex- 

 ternal orbital angle, ten teeth. External buccal angle 

 has about six teeth. — i^D. dcntatus.) 



I. Dilocarcinus marg-aritifrons. 



Dilocarciinis margatitifrons . . Ortmann. 



The front is cut into two rounded lobes, with pearl- 

 like tubercles on anterior margin. 



The right hand is usually the largest ; the fourth joint 



