Boone, Crustacea, Cruises of "Eagle" and "Ara," 1921-28 99 



Synonymy. — Mithrax holderi Stimpson, Bull. Mus. Comp. Zool., vol. 

 2, p. 117, 1871. — Rathbun, Bull. Lab. Nat. Hist. State Univ. Iowa, 

 vol. 4, p. 259, pi. 3, fig. 2, 1898 ; Bull. U. S. Fish. Comm., vol. 20, pt. 

 2, p. 69, 1901 ; Bull. 129, U. S. Nat. Mus., p. 392, pi. 138, fig. 1 

 and fig. 2, pi. 257, fig. 2, 1925. 



Subgenus : MITHRACULUS. as restricted by Rathbun. 

 Mithrax (Mithraculns) corjrplie (Herbst). 



Plate 30, fig. A. 



Diagnostic chaeacters : Mottled green ; legs shaggy ; body averages 

 about the size of a penny. Carapace very nodose, one-third wider than 

 long; rostrum small; three anterolateral lobes. 



Type : Herbst failed to state his type locality ; his type was depos- 

 ited in the Berlin Museum. 



Distribution : From southern Florida throughout the West Indies 

 to Sao Paulo, Brazil, bathymetric occurrence, shore line to 30 fathoms. 



Material examined: Five small specimens, one egg-laden, caught 

 in dragnet. Port Antonio, Jamaica, February 17, 1926. 



Color : Upper surface marbled in two tones of moss-green ; under- 

 side white; tips of the dactyli touched with coral and tipped with 

 white. Occasionally a specimen is found that is maculated with tiny 

 bluish flecks. 



This little marbled green spider crab is very abundant in West 

 Indian waters but is quite inconspicuous because of its coloration 

 and the fact that its legs are very shaggy with algae-like setae. It 

 dwells in the cavities of corals, sponges and rocks, and on sandy and 

 muddy shallows. 



Technical description : Carapace approximately one-third wider 

 than long and very nodose. The interorbital region is wide ; the ros- 

 trum consists of two truncated teeth separated by a small sinus; 

 posterior to each horn there is a sharp denticle. There is a single 

 suture on the upper orbital margin ; the orbital angles are blunt ; the 

 inner inferior orbital lobe is slightly more advanced than the superior 

 one. The basal antennal joint is subtriangulate. The anterolateral 

 margins are armed with three nodular lobes which are the termina- 

 tions of three oblique elevations separated by deep furrows that cross 



