^ 

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THE SPIDER CRABS OF AMERICA 285 



article and the orbit; this article i^ much longer than the preceding, 

 wide, and very depressed; next article shorter, reaching about to end 

 of rostrum, or even surpassing it. Antennules and mouth parts as 

 in Pisa. Epistome almost linear. Sternal plastron as long as wide. 



Chelipeds short, rather stout; fingers slender, elongate, slightly- 

 curved and finely denticulate on the inner border. Legs diminishing 

 progressively in length, the first being longer than the cheliped; 

 merus and carpus very wide and compressed, propodus cylindrical, 

 dactylus short, very crescentic, unarmed below. Abdomen 7- 

 segmented in both sexes. (After Milne Edwards and Lucas.) 



Known only on the Pacific coast of South America from Panama 

 to the Straits of Magellan, including the Galapagos Islands. 



PISOroES EDWARDSn (Bell) 



Plate 236 



Hyas edwardsii Bell, Proc. Zool. Soc. London, vol. 3, 1835 (1836), p. 171 

 (type-localities, Valparaiso and Galapagos Islands; types not extant) ; 

 Trans. Zool. Soc. London, vol. 2, 1836, p. 49, pi. 9, fig. 5. 



Pisoides tuberculosus Milne Edwards and Lucas, d'Orbigny's Voy. 

 I'Am^r. M^rid., vol. 6, pt. 1, 1843, p. 11; vol. 9, atlas, 1847, pi. 5, figs. 1-ld 

 (type-locality, les cotes du Chili; type in Paris Mus., cotype in Mus. Phila, 

 Acad. Nat. Sci.). — Nicolet, in Gay, Hist. Chile, Zool., vol. 3, 1849, p» 

 134. — A. Milne Edwards, Crust. R6g. Mex., 1875, p. 75, pi. 16, figs. 

 5-56. — Lbnz, Zool. Jalirb., Sappl. 5, vol. 2, 1902, p. 757. — Rathbun, Proc. 

 U. S. Nat. Mus., vol. 38, 1910, pp. 572 and 616. 



Pisoides edwardsii Dana, U. S. Expl. Exped., vol. 13, Crust., pt. 1, 1852, 

 p. 87; atlas, 1855, pi. 1, figs. 2o and 26. — Miers, Proc. Zool. Soc. London, 

 1881, p. 63.— Rathbun, Proc. U. S. Nat. Mus., vol. 38, 1910, pp. 572and 

 613. 



Pisoides edwardsi Miers, Proc. Zool. Soc. London, 1881, p. 66. 



Diagnosis. — No preocular spine; postocular spine large, sharp. 

 Basal antennal article nearly as broad as long, and with a prominent 

 tubercle at its antero-external angle. Rostral horns flat. 



Descrijition. — Carapace and ambulatory legs covered with a short, 

 dense velvet in the midst of which are some elongate hairs recurved 

 at the end. Carapace dotted beneath with small round pits which 

 serve for the insertion of the hairs. Branchial, gastric and genital 

 regions ornamented with prominent tubercles. Anterior margin of 

 merus of chelipeds armed at the extremity with a strong spine. Merus 

 of first ambulatory leg strongly compressed, its upper margin cristate; 

 merus of remaining legs wide, flat and rounded above; on the outer 

 margin of the merus a very pronounced spine especially in the first 

 pair. Carpus short, wide; propodus elongate, cylindrical. Abdo- 

 men of both sexes entirely smooth. (Milne Edwards and Lucas.) 



Branchial regions tumid, bearing two or three small, faint tubercles. 

 The cardiac region is a broad prominence with rounded surface^ and 



