THE DECAPOD AND STOMATOPOD CRUSTACEA 



135 



Front very narrow, not linear nor spatuliform, but subtriangular, at 

 base or posteriorly less than one-fifth the width between the antero- 

 lateral angles of the carapace, anteriorly truncate or nearly so ; sides 

 oblique and almost straight. Superior orbital surface, or eyebrow, 

 shallow, not varying much in length throughout its width ; margins 

 finely granulate. Inferior margin of orbit with large truncate tuber- 

 cles, increasing in size and distance apart towai'd the outer extremity. 



Large cheliped very heavy. Merus and carpus elongate, thick, 

 rugose on the outer surface, and without armed margins. Outer sur- 

 face of palm coarsely tuberculate on its upper half, the tubercles 

 gradually becoming fine granules below ; upper and lower margins 

 set off by deep grooves. Inner surface of palm with a ridge marked 

 by a single line of large tubercles, leading obliquely upward from the 

 lower mai"gin to the carpal cavity, where it turns at a little less than a 

 right angle and is continued less than half way to the upper margin, 

 or when continued further, the tubercles are obsolete. On the palm 

 at the base of the dactylus are two tuberculate lines, the distal one very 

 short ; both are slightly oblique to the lower margin. In full grown 

 males the fingers are very long, the lower margin of the propodus 

 sinuous, the pollex bent down for its distal third. The dactylus 

 equals or overreaches the pollex. The prehensile tubercles are irreg- 

 ular, but not sti-ikingly so. The dactylus is roughened at its base on 

 the upper side, and has a short longitudinal groove on the outer side 

 below the upper margin. 



The smaller cheliped is rather long, the fingers longer than the 

 palm and somewhat gaping to the tips. The meral joints of the am- 

 bulatory legs are dilated and very broad, especially those of the second 

 and third pairs. 



TABLE OF DIMENSIONS. 



Sexual and age variations. — Old males show a tendency to 

 widen behind the antero-lateral angles ; this tendency is stronger on 



