THE GEAPSOID GRABS OF AMERICA. 337 



a longitudinal series on hand and dactylus. Lobe on basal joints of 

 legs armed above with a spine; anterior margin of merus joints ir- 

 regularly dentate or spinose. 



Measurements. — Male (2476), extreme length of carapace 63.5, 

 width of same 6D.5, fronto-orbital width 39.5 mm. 



Habitat. — In the holes excavated by the surf on the rocky coast of 

 Table Bay (Krauss). llather common about the rocks at half tide 

 in Simons Bay (Stimpson). 



Range. — Chile (Milne Edwards) : Coquimbo and Island of Juan 

 Fernandez (Porter). Also Cape of Good Hope; New South Wales; 

 Tasmania; New Zealand; Tongatabu, 



Material exainined. — 



Illawarra, New South Wales, Australia; U. S. Exploring Exped.; 

 three specimens (one female) (2379). 



Tasmania; received from Mus. Comp. Zool. ; one male (247G). 



Bay of Islands, New Zealand; U. S. Exploring Exped.; one male, 

 <me female (2360). 



Genus PERCNON Gistel. 



Acanthop'us dk Haan, Fauna Japon., Crust., 1833, p. 5; 1835, p. 29; type, A. 



clavimana de Haan, lS3o= planissiniwn (Hei'bst, 1804). Acanthopus 



pi'eoccupied by Klug, Illig. Mag., vol. 6, 1807, for genus of Hynienop- 



tera. 

 Percnon Gistel, Naturg. Thierreichs, 1848, p. 8; type, P. planissimum 



(Herbst). 

 Leiolophus Mieks, Cat. Crust. New Zealand, 187G, p. 4G; type, L. planis- 



simus (Herbst). 



Carapace extremely flat and depressed, being quite disk-like. 

 Interantennular septum narrow. Epistome almost linear. Merus 

 of external maxillipeds very small, much narrower than the ischium, 

 and disposed obliquely in repose; exognath extremely short and 

 slender. Chelipeds and legs, though in places spiny, not rugose. 

 Legs much slenderer, and though the meropodites are broad, they 

 are very thin. The appendages of the first segment of the male 

 ab<Jomen end in a claw. 



Distribution. — As Plagusia, but not in the Mediterranean. 



PERCNON GIBBESI (Milne Edwards). 



SPRAY CRAB (Jarvis). 



Plate 105. 



Acanthopus gibbesi Milne Edwards, Ann. Sci. Nat., ser. 3, Zool., vol. 20, 

 1853, pp. 180 and 146 (type-locality, Antilles; type in Paris Mus.). 



Leiolophus platiissimus Miers, Ann. IMag. Nat. Hist., ser. 5, vol. 1, 1878, 

 p. 153 (part). Not Cancer phinissinius Horbst, 1804. 



Percnon planissimum Rathbin. Proc. IT. S. Nat. Mus.. vol. 22, 1000, p. 281 

 (part). 



onso.'?— 17 22 



