THE CANCROID CRABS OF AMERICA 423 



KEY TO THE SPECIES OF THE GENUS EURYTIUM 



A^ Carapace very convex. 



B'. Carapace widest behind tips of teeth of last pair limosum, p. 423. 



B2. Carapace widest at tips of teeth of last pair tristani, p. 425. 



A2. Carapace nearly flat. Carapace widest at tips of teeth of last pair 



affine, p. 425. 



ANALOGOUS SPECIES ON OPPOSITE SIDES OF THE CONTINENT 



Atlantic Pacific 



limosum tristani 



EURYTIUM UMOSUM (Say) 



Plate 176, Figures 1 and 2 



Cancer limosa Say, Journ. Acad. Nat. Sci. Philadelphia, vol. 1, 1818, p. 446 

 (type-locality, "Inhabits shores of the northern states;" type not extant). 



Panopeus limosus Milne Edwards, Hist. Nat. Crust., vol. 1, 1834, p. 404. 



Eurytium limosum Stimpson, Ann. Lye. Nat. Hist. New York, vol. 7, 1859, p. 

 56 [10].— A. Milne Edwards, Crust. R^g. Mex., 1880, p. 332, pi. 60, 

 fig. 2, 2a. 



Diagnosis. — Carapace very convex, widest behind tips of teeth of 

 last pair. Frontal lobes undivided. Sinus between coalesced teeth 

 shallow. 



Description. — Carapace very convex in an antero-posterior direc-. 

 tion; surface smooth to eye, but under the lens densely granulate, the 

 granules coarser near frontal and antero-lateral margins; two feeble 

 epigastric lobes; mesogastric and cardiac regions outlined. Front 

 one-fourth the width of carapace. Antero-lateral margin about two- 

 thirds the length of postero-lateral, bordered by a raised line of 

 granules; first tooth small, triangular; second lobiform, separated 

 from first by a shallow sinus; third obtuse, fourth subacute, both with 

 arcuate outer margin; fifth more prominent, acute, pointing forward. 



Granulation of chelipeds fine and reticulate; upper margin of merus 

 coarsely tuberculate, a strong subdistal tooth; no groove on carpus, a 

 narrow inner spine; fingers pointed, deflexed, a large basal tooth on 

 major dactyl; color of immovable fingers stopping short of palm. 



Color. — Carapace a brilliant purplish blue; wrist and hand bluish; 

 fingers white except proximal upper half of movable finger pink; lower 

 portion of chelipeds and also carpal tooth orange-yellow. 



Measurements. — Male (44184), length of carapace 26.6, width of 

 same 42.8, fronto-orbital width 21.5, width of front 10 mm. 



Habitat. — In muddy or marshy banks, a little below high-tide mark, 

 in burrows partially filled with water. 



Range. — New York (De Kay) to State of Sao Paulo, Brazil; Baha- 

 mas; Bermudas. 



Material examined. — 



NEW JERSEY.— Thomas Say collector; 2 males (Phila. Acad.). 

 The larger one is 45 mm. wide, while Saj^'s measured type was 33.8 

 mm. wide. 



