NO. 1136. OBSERVATIONS ON THE ASTACIDJE— FAXON. 691 



with scattered setse; margius slightly raised, convergent, lightly con- 

 vex, armed near the tip with a pair of small, blunt denticles; acumen 

 short, subacute. Suborbital angle prominent, but rounded off, unarmed 

 with tooth or spine. Postocular ridges obsolete except their anterior 

 ends, which form a tubercle on each side of the base of the rostrum — a 

 tubercle channeled along its outer face and terminating anteriorly in 

 an obsolescent tooth. Carapace smooth and lightly punctate above, 

 minutely granular on the sides. Cervical groove sinuous, no lateral 

 spine. Areola very broad. Distance from tip of rostrom to cervical ^^^, 

 groove upward of twice and a half as long as the areola. Abdomen 

 smooth, pleurte rounded. Sides of telson slightly convergent, armed 

 with a spine on each side, one-third way from the distal end; distal 

 border truncate, posterolateral corners rounded. Anterior process of 

 the epistome triangular, sides straight or slightly convex, tip blunt or 

 slightly truncate; a slight furrow divides the anterior process from the 

 body of the epistome, and the latter is divided in halves by a longi- 

 tudinal depression. Basal segment of antenna armed with a sharp 

 spine in front of the orifice of the green gland; another spine lies at 

 the base of the outer edge of the antennal scale; the antennal scale is 

 of moderate size, a little louger than the rostrum, broadest near tbe 

 middle, its outer margin slightly convex, ending in a small apical spine. 

 Third pair of maxillipeds hairy within and below. Eight and left cheli- 

 peds very unequal, the left usually the larger; lower margins of the 

 merus denticulate, upper margin furnished with one small tooth near 

 the distal end of the segment; outer and inner faces smooth; carpus 

 marked with a conspicuous longitudinal groove on its upper outer 

 face, and with a few small, blunt tubercles on its inner margin ; lower 

 external border of carpus short, rounded, and protuberant; chehe with- 

 out prominent tubercles or spines, but when viewed under a lens the 

 surface is finely squamoso-tuberculate proximally, punctate distally; 

 the superior and inferior borders of the chela are rounded, the fingers 

 setose along their cutting edges; the fingers of the left (larger) chela 

 are stout, somewhat gaping, with one evident round tubercle on the 

 prehensile margin; the fingers of the right (smaller) chela are rela- 

 tively longer and slenderer and are devoid of tubercles on the prehen- 

 sile margins. The median longitudinal ridge on the inner blade of 

 the last abdominal appendages ends in a small spine near the posterior 

 border. 



Length of a male 83 mm.; cephalo-thorax 38 mm.; abdomen 45 mm.; 

 length of rostrum 9 mm.; width of rostrum at base 5 mm.; length of 

 telson 12 mm.; width of telson at base 11 mm.; from tip of rostrum 

 to cervical groove 28 mm.; from cervical groove to posterior margin 

 of carapace 10 mm.; width of areola 8.8 mni.; length of left cheli- 

 ped 67 mm. (merus 15 mm., carpus 11 mm., chela 32 by 16 mm., 

 dactylus 20 mm.); length of right cheliped 51 mm. (merus 11 mm., 

 carpus 9 mm., chela 25 by 8.5 mm., dactylus 16 mm.). 



The largest individual (a male) is 97 mm. long. 



