A MONOGRAPH OF THE EXISTING CRINOIDS 461 



united for the proximal two-thirds. The first syzygial pair (composed of brachials 

 3 + 4) is from half again to twice as broad as long. The next 3 brachials are oblong, 

 about two and one-half times as broad as long, those succeeding becoming very 

 obliquely wedge-shaped or triangular, twice as broad as long, after the proximal 

 third of the arm becoming gradually less obliquely wedge-shaped, but of the same 

 relative length, and slightly longer distally. The division series and first 2 brachials 

 are perfectly smooth dorsally, but from the fourth onward the brachials have moder- 

 ately produced and overlapping distal edges. 



Syzygies occur between brachials 3 + 4, again from between brachials 11 + 12 

 to between brachials 15 + 16 (usually in the vicinity of the thirteenth brachial), and 

 distally at intervals of from 4 to 9 (usually 4) muscular articulations. 



P D is moderately stout basally, but tapers rapidly and is exceedingly slender in 

 the distal two-thirds. The terminal comb consists of 7-1 1 moderately large roundedly 

 spatulate teeth. The pinnule is 20 mm. long. P P and PI are nearly as long, similar, 

 but less stout basally. P 2 is about 7 mm. long, slender and delicate. The following 

 pinnules gradually become longer and stouter, with large gonads, and then more 

 slender again distally. The distal pinnules are very slender, and about 10 mm. long. 

 From P 3 onward the pinnules have the third-fifth or third-seventh segments produced 

 into long high narrow carinate processes which on the lower segments may be as high 

 as the width of the segment that bears them. This modification of the proximal 

 segments gradually dies away after about the middle of the arm. The terminal comb 

 persists to about P 7 . 



The disk is from 25 to 30 mm. in diameter, and carries a variable number of 

 small granules, which are especially numerous along the ambulacral grooves. The 

 mouth is interradial. A varying number of the posterior arms are ungrooved. 



The color in alcohol as described by Carpenter is darkish brown with a dark 

 mediodorsal line, the pinnules sometimes tipped with green. A dry specimen at 

 hand from Torres Strait is olive brown, darker on the ventral surface, the pinnules 

 tipped with brilliant greenish yellow; the gonads are brown, but bright red by trans- 

 mitted light. Another dry example from the same locality is light olive brown with 

 a dark mediodorsal line, becoming blackish in the outer half of the arms; the pinnules 

 are buff and black in broad bands. 



Notes. The specimen from the Abrolhos Islands has 73 arms which are about 

 85 mm. long. The cirri are VI, 14-16, from 10 mm. to 12 mm. long. 



The specimen from Freycinet Reach, Shark Bay, has about 120 arms of which 

 the anterior are about 120 mm. and the posterior about 80 mm. in length. The left 

 posterior ray and its derivatives, and the adjacent halves of the neighboring rays, are 

 devoid of ambulacral grooves. Many of the arms on the other rays have rudimen- 

 tary ambulacral grooves, or none at all. The genital pinnules are rarely grooved. 

 Wherever it is exposed the dorsal perisome is heavily plated. The centrodorsal is 

 thin discoidal, 4.5 mm. in diameter, with the dorsal pole strongly concave. Three 

 cirri, which are equally spaced, remain. These are comparatively long, 13 mm. in 

 length, and moderately stout, with 16 segments, of which the first is short, those 

 following gradually increasing in length and becoming about as long as broad on the 

 fourth; the fifth-eighth are slightly longer than broad; those succeeding are about 



