CRUSTACEA NORTH PACIFIC EXPLORING EXPEDITION 121 



Genus XAUTILOGRAPSUS Milne Edwards 



197. NAUTILOGRAPSUS MINUTUS ' Milne Edwards 



Cancer minutus Linn.£us. 



Grapsns cincrcus Say. 



Nautilograpsus miymtus Milne Edwards. Hist. Nat. des Crust., n. 90; 



Mel. Carcin., p. 140. 

 Planes minutus Bell, Dana, U. S. Expl. Exped., Crust., i, 346. 



Our largest specimen, a male, has the following dimensions: 

 Length of carapax, 0.74; breadth, 0.79 inch. It is, therefore, not 

 "beaucoup plus longue que large," as stated by jNIilne Edwards. 

 The tooth behind the orbital angle is often nearly obsolete. 



It is common on floating logs, seaweed (Sargassum), etc., in the 

 North Atlantic between the 20th and 36th parallels of latitude. We 

 did not observe it in the South Atlantic. 



198. NAUTILOGRAPSUS ANGUSTATUS ' Stimpson 



Plate XVI, Fig. i 



XautilograpsHs angusfatus Stimpson, Proc. Acad. Nat. Sci. Phila., x, p. 

 103 [49]. 1858. 



Carapax smooth, narrow ; proportion of breadth to length, i : 1.14. 

 Branchial regions lightly striated transversely. Gastric lobules 

 sufficiently distinct, but not prominent. Front narrow, much ad- 

 vanced, its margin lightly sinuated. Frontal region concave. Lat- 

 eral margins nearly straight, parallel ; a single small tooth behind 

 the orbital tooth ; margin acute between the teeth and for a little dis- 

 tance behind the posterior tooth, terminating at a slight oblique 

 sulcus on the branchial region, perhaps indicating a third, obsolete 

 tooth. Behind this point the margins are obtuse. Ambulatory feet 

 rather less broad than in other species of the genus. The dimen- 

 sions of our unique (female) specimen, which is probably immature, 

 are: Length of carapax, 0.24; breadth, 0.21 inch. 



It differs from .V. [^usilliis in its less prominent second marginal 

 tooth ; from .V. cyanens in its more advanced front and less smooth 

 surface. From both these species, and from A', in in it tits, it differs 

 in its narrower carapax. 



It was taken in the North Pacific Ocean, in latitude 34° N., longi- 

 tude 151° W. 



^Planes minutus (Linnaeus). 



