THE GBAPSOID CRABS OP AMERICA. 253 



oblique at the sides; from each ridge arises a fringe of short hair, 

 which lies flat. 



Front almost straight-edged, with the corners obliquely cut off. 



Carpus armed with an inner spine. Three long and some short 

 longitudinal ridges on outer surface of chelae, inner surface smooth ; 

 fingers gaping, strongly toothed. Upper margin of merus joints 

 short-hairy, a moderate or feeble subterminal tooth, lower margin 

 irregularly toothed at end, next two joints long-hairy; dactyli armed 

 with stout thorns. 



Measurements. Type, length of carapace 12, width of same 14 mm. 



Range. Cuba (von Martens). 



Genus PLANES Leach. 



Planes BOWDICH, Excursions in Madeira and Porto Santo, 1825, pp. XI and 

 15, pi. 12, figs. 2a and 2b; type, P. clypeatus Bo\\dich=minutus (Lin- 

 naeus). 



Nautilograpsus MILNE EDWABDS, Hist. Nat. Crust., vol. 2, 1837, p. 89 ; type, 

 2V. minutus (Linnaeus). 



Carapace quadrate-oval, about as long as broad, convex, regions 

 scarcely defined. Lines on the carapace faint. Sides convex. An- 

 tero-lateral angle acute; behind it a slight notch forming a small 

 tooth. 



Front about half width of carapace, gently deflexed, lobes at line 

 of flexion almost obsolete. 



Orbit with a slight notch below near the outer angle ; inner hiatus 

 wide. Palpus articulating at middle of anterior margin of merus of 

 outer maxillipeds. 



Legs much flattened, somewhat natatory. Teeth on merus joints 

 more feeble than in Pachygrapsus. 



Otherwise much as in that genus. 



Contains two species which are pelagic, one of them of almost 

 world-wide distribution. Species on both sides of the continent: 

 minutus. 



KEY TO THE SPECIES OF THE GEN0S PLANES. 



A 1 . Carapace uniformly convex ; postero-lateral margins arcuate_minfs, p. 253. 



A 1 . Carapace depressed about the middle ; postero-lateral margins nearly 



straight marinus, p. 258. 



PLANES MINUTUS (Linnaeus). 



Plate 63. 

 GULF-WEED CRAB ; TURTLE CRAB ; COLUMBUS'S CRAB. 



Cancellus marinus minimus quadratus SLOANE, Nat. Hist. Jamaica, vol. 2, 



1725, p. 270, pi. 245, fig. 1. 

 Turtle Crab BKOWNE, Hist. Jamaica, 1756, p. 421, pi. 42, fig. 1. 



