366 BULLETIN 129, UNITED STATES NATIONAL MUSEUM 



PITHO MIRABILIS (Herbst) 



Plate 128; fig. 3; plate 129, fig. 3; plate 253, fig. 1 



Cancer mirabilis Herbst, Naturg. d. Krabben u. Krebse, vol. 2, 1794, 



p. 152 (part), pi. 37, fig. 3 (type-locality not known; types in Berlin 



Mus.). 

 Othonia mirabilis Gerstaecker, Arch. f. Naturg., vol. 22, pt. 1, 1856, 



p. 113 (part). 

 Othonia sexdentata A. Milne Edwards, Crust. Reg. Mex., 1875, p. 117 



(part) . 

 Othonia rotunda Rathbun, Proc. U. S. Nat. Mus., vol. 15, 1892, p. 258, 



pi. 36, fig. 1 (type-locality. Key West, Florida; holotype. Cat. No. 15807, 



U.S.N. M.). 

 Pitho mirabilis Rathbun, Bull. Lab. Nat. Hist. State Univ. Iowa, vol. 4, 



1898, p. 258. 



Diagnosis. — Carapace swollen, as broad as long, covered with fine 

 bead granules. Lateral teeth diminishing in size from the anterior 

 to the posterior, their edges denticulate. 



Description. — Carapace as broad as long, widest at fourth antero- 

 lateral tooth, much swollen in both directions, transversely rising 

 abruptly from bases of lateral teeth, longitucUnally rising in almost 

 an equal curve from behind the front and from posterior margin. 

 Regions faintly indicated. Carapace covered with granules more 

 thickly set on posterior half; long, fine hairs proceed from the top 

 of the granules. Along the outer margins of the gastric lobes, 

 bunches of granules beset with coarse hairs form a broad line which 

 is continued to rostrum. Rostral teeth sharp, produced beyond 

 orbital angles. Preorbital tooth obtuse, less produced than post- 

 orbital, which is subacute. Antero-lateral teeth usually five, acute, 

 separated to their bases, the first the largest, the others as a rule 

 decreasing in size to the last, the tips making a single curve. An- 

 terior margins of teeth thickened, Antero-lateral margin marked 

 by inconspicuous granules irregularly placed, giving the teeth the 

 appearance of being themselves minutely dentate. Basal article of 

 the antenna %vith a sharp, longitudinal groove through the middle; 

 tooth at distal extremity slightly more produced than upper inner 

 angle of orbit and visible in a dorsal view; outer lobe of first movable 

 article directed forward (fig. 117, c) . Abdomen and sternum minutely 

 pubescent; abdominal appendages in male diverging slightly at 

 distal ends hooked at tips (fig. 116, d). 



Chelipeds in both sexes slender, longer than ambulatory legs, 

 finely punctate, upper margin with thinly scattered hairs; arm 

 angular, a few small tubercles on the upper margin; hand slightly 

 tapering distally; fingers in male gaping for the proximal third, a 

 tooth on dactyl; in the female, fingers evenly dentate and in con- 

 tact for nearly their whole length, a slight gape at proximal end. 



