THE CANCROID CRABS OF AMERICA 513 



PILUMNUS GEMMATUS Stimpson 



Plate 207, Figures 1-3 



Pilumnus gemmatus Stimpson, Ann. Lye. Nat. Hist. New York, vol. 7, 1860, 

 p. 214 [86] (type-localities, St. Thomas and Tortugas; types not extant). — 

 Rathbun, Bull. U. S. Fish Comm. for 1900, vol. 20, pt. 2 (1901), p. 38.— Not 

 A. Milne Edwards, Crust. Reg. Mex., 1880, p. 290, pi. 51, fig. 4-46. 



Diagnosis. — Dorsal aspect showing small red tubercles set in close- 

 cut velvet. Outer surface of both hands entirely covered with tuber- 

 cles and hair. Fingers deeply grooved. 



Description. — Carapace rather narrow, covered as are also the 

 chelipeds and legs with a short, close pubescence (with occasional 

 stout and long cylindrical setae), which does not conceal boundaries of 

 regions and the small red beads or tubercles scattered on anterior two- 

 thirds of carapace (3 to 6 on each areolet), upper and outer surfaces of 

 chelipeds and upper surface of legs. On the latter the tubercles or 

 granules are much smaller than elsewhere. Frontal lobes subtri- 

 angular, granulate on margin, more advanced near median line; in- 

 terspace large, V-shaped; a transverse row of stout setae behind each 

 lobe. Upper orbital margin with two or three red tubercles, lower 

 margin finely denticulate, a shallow outer notch. Antero-lateral 

 projections four, short, stout; tips varying from blunt in first and 

 second tooth to acute in the last. 



Entire outer surface of both hands tuberculate, the tubercles grow- 

 ing smaller and more numerous toward lower margin. Propodal 

 finger horizontal, lower edge slightly arcuate, tip slightly upcurved. 

 Both fingers deeply grooved; tubercles on upper portion of basal half 

 of dactylus, a few on outer surface of immovable finger, where in small 

 specimens they form in two rows on the ridges. Outer lower margin 

 of arm with a broad band of tubercles and granules. 



Color. — Pubescence cream-colored or whitish; granules, tubercles 

 and spines all bright ruby red. (Stimpson.) Fingers fight brown. 



Measurements. — Female (56900), entire length 10.6, entire width 

 13.5, fronto-orbital width 9, width of front 4 mm. 



Range. — Tortugas, Florida; Culebra Island to Curagao. 



Material examined. — Tortugas, Florida; June 5-8, 1893; Biological 

 Expedition, State University of Iowa; 1 male (Mus. S.U.I.). 



Tortugas, Florida; W. L. Schmitt; gift of Carnegie Institution: Six 

 dredge hauls W. of Loggerhead Key, off dock and N. of lighthouse 

 pier; 8-5 feet; August 3, 1924; 1 young female (60946). Stomach of 

 fish No. 121, gray snapper, Neomaenis griseus (L'nnaeus), outer 

 Lighthouse Reef ; June 7, 1925; 1 female (60945). Mid-section of Bush 

 Key reef inside, 3 feet before eelgrass; washed from weed and rocks; 

 August 1, 1924; 4 specimens (62555). 



Ensenada Honda, Culebra Island; February 10, 1899; Fish Hawk; 

 1 female (24370). 



79856—30 34 



