348 CRUSTACEA. 



The male abdomen is so different in shape from the minutus, and 

 the colour also, so unlike, that we believe the two to be different 

 species. 



P. cyaneus, DANA, Proc. Acad. Nat. Sci. Philad., 1851, v. 250. 



GENUS HEMIGRAPSUS, Dana. 



Carapax fere Icevis, lineis transversis non notatus, f route fere recto, late- 

 ribus arcuatis. Maxillipedes externi rhombicd hiantes, articulo Btio 

 arbiculato-cordato. Antennae internee transversce. 



Carapax nearly smooth, not marked by transverse lines, front nearly 

 straight, sides arcuate. Outer maxillipeds separated by a large 

 rhomboidal space, third joint orbiculato-cordate. Inner antennge 

 transverse. 



Hemigrapsus includes part of the species referred to Edwards's 

 Cyclograpsus, as explained on page 331. The process outside of the 

 outer antennae is transverse, triangular, and sets closely against the 

 first joint of the antennae. The abdomen of the male is rather narrow, 

 and at base it does not quite reach to base of posterior legs. Carpus 

 rounded on inner side. Part of De Haan's Grapsi belong to this 

 genus. 



HEMIGRAPSUS SEXDENTATUS (Edw.}, Dana. 



Plate 22, fig. 2 a, male, natural size ; &, leg of second pair, ibid. ; c, 

 leg of fifth pair, ibid. 



Bay of Islands, New Zealand. 



Length of carapax, nine lines ; breadth, ten lines ; length of front, 

 four and two-thirds lines. Colour of back, dark brown to black 

 clouded with gray, or dirty white ; legs black, clouded or banded with 

 dirty white. Front considerably inclined, straight; antero-lateral 

 margin two-emarginate, teeth triangular, subacute. Legs naked, 



