STALK-EYED CRUSTACEA 281 



3. Geograpsus. 



Geograpsns . . Stimpson, Miers, Kingsley. 

 Discoplax ... A. Milne Edwards. 

 OrihograpsHs . . Kingsley. 



Carapace depressed, plicated only near the lateral 

 margins, with the antero-lateral margins straight or 

 arcuated only at the hepatic regions, posteriorly nearl}' 

 straight ; they are armed with a single tooth behind the 

 external orbital tooth. Front of moderate width, and 

 deflexed. The basal joint of external antennae is short, 

 and but slightly produced at its antero-external angle. 

 Antennae not excluded from the orbit. The third and 

 fourth joint of the external maxillipedes narrow, especially 

 the fourth joint, which is slender and elongated, distally 

 truncated, articulating with the next joint at or near its 

 antero-external angle. The fingers of the first pair of 

 legs have acute tips. 



Range. — Atlantic and Pacific Oceans. 



Synopsis of the Species. 



A. Sides of carapace straight. — (G. ///////.) 



B. Sides of carapace bowed in anterior part. — (6". 



I. Geograpsus hillii. 



Geograpsns hillii . . . Miers. 

 Orthograpsns hillii . . Kingsley. 



Suprafrontal lobes moderate ; front straight, narrow, 

 deflexed. Sides of carapace straight ; postorbital tooth 

 small. Fourth joint of external maxillipedes a little 

 longer than broad. First pair of legs have the hands 



