372 



BULLETIN 129, UNITED STATES NATIONAL MUSEUM 



Description. — Allied to P. anisodon, but the second or smallest of 

 the lateral spines is suppressed, leaving four spines, which are nar- 

 rower, less flattened and more outstanding than in anisodon. All 

 four spines are of large size, second and third largest, fourth as long^ 

 as first and more slender; between first and second spines a tubercle 

 may be present on one or both sides, corresponding to the small spine 

 or tooth similarly placed in P. anisodon. Carapace wider than in 

 anisodon, owing to the widespread spines, the width being greater 

 than the length in the largest specimens, while in P. anisodon the 

 width is much less than the length. 



Teeth of rostrum short, blunt or subacute, separated by a wide V. 

 Orbital teeth also blunt. 



The fourth abdominal segment of the male is longer and narrower 

 than in anisodon. 



Measurements of carapace of cotypes. — Female, length 20.7, width 

 20.3, width without spines 17.4, fron to-orbital width 11 mm. Sex 

 unknown, length 27, width 28.7, width without spines 24, fronto- 

 orbital width 14.8 mm. 



Measurements of carapaces of Pitho quadridentata and anisodon of approximate size 



Range. — Jamaica. 



Material examined. — 



Port Royal, Jamaica; P. W. Jarvis; 3 males, 2 females (19404), 



Kingston Harbor, Jamaica; T. H. Morgan; 1 male (17204). 1896; 

 F. S. Conant; 1 male (19585). 



West Indies; 2 large females and 2 very large carapaces (cotypes^ 

 Brit. Mus.). 



PITHO LAEVIGATA (A. Milne Edwards) 



Plate 132, figs. 3 and 4; plate 133, fig. 3; plate 250, figs. 11-13 



Cancer mirabilis Herbst, Naturg. d. Krabben u. Krebse, vol. 2, 1794, p. 152 



(part), not pi. 37, fig. 3. 

 Othonia laevigata A. Milne Edwards, Crust. Reg. Mex., 1875, p. 116; 1878, 



pi. 24, figs. 2-26 (type-locality, Antilles; holotype in Paris Mus.). 



Diagnosis. — Five lateral teeth subequal; second and third united 

 at base. Front narrow. Outer margin of lobe of first movable 

 joint of antenna very arcuate. 



Description. — Carapace subcircular, broader than long, the outer 

 margins of the outer orbital teeth converging anteriorly, the fronto- 



