A. H. CLARK : THE CRINOIDS OF THE INDIAN OCEAN. 109 



Radials concealed, or just visible beyond the centrodorsal ; IBr, oblong, 

 very short, in close lateral apposition; IBr, very broadly pentagonal, almost 

 triangular, the lateral edges not quite so long as those of the IBr,, about two 

 and one half times as broad as long : IIBr 4 (3+4) ; IIIBr 4 (3+4) : division 

 series and first two brachials in close lateral apposition and laterally flattened, 

 the dorsal carination of Pp only being visible exteriorly ; synarthrial tubercles 

 usually prominent. 



Twenty to twenty-five arms 150 mm. long : first brachial slightly wedge- 

 shaped, short, about three times as broad as its exterior length, almost entirely 

 united interiorly ; second about the same size, but more pronouncedly wedge- 

 shaped ; third and fourth (syzygial pair) oblong, half again as broad as long ; 

 next five or six brachials oblong, nearly or quite four times as broad as long, 

 then slowly becoming wedge-shaped and then almost triangular, four times as 

 broad as long , soon becoming wedge-shaped again and , in the outer half of the arm , 

 oblong and very short, though somewhat longer again terminally. The proximal 

 discoidal brachials are somewhat swollen, and most of the brachials have slightly 

 overlapping distal ends. Syzygies occur between the third and fourth brachials, 

 again between the thirteenth and fourteenth to thirty-first and thirty-second 

 (usually somewhere between the sixteenth and twenty-fifth , with sometimes an 

 extra one from two to four or five brachials beyond the first), and distally at 

 intervals of from two to thirteen (usually eight to twelve) oblique muscular 

 articulations. 



Pjj 7 mm. long, moderately stout basally but tapering rapidly and becoming 

 slender in its distal half, with about twenty-five segments, which are at first 

 three times as broad as long, becoming twice as broad as long at the sixth, and 

 squarish in the terminal portion ; some of the lower segments are bluntly 

 carinate ; P, 10 mm. long with thirty segments, slightly less stout basally than 

 Pd and tapering somewhat less rapidly ; the segments are at first about twice as 

 broad as long, becoming as long as broad at about the eighth, and somewhat 

 longer than broad terminally ; P.j 15 mm. long, stouter than P,, tapering evenly 

 to a delicate tip, with thirty segments, at first about half again as broad as long, 

 becoming squarish at the eighth or ninth, and about twice as long as broad at 

 the tip : P.^ 22 mm. long, stouter than the preceding, with thirty segments, at 

 first broader than long, becoming squarish at the tenth and longer than broad 

 terminally ; the pinnule is more or less carinate in its proximal half and has a 

 moderate supplementary ridge on the distal half of the outer side ; P^ resembling 

 P,, but very slightly longer, and proportionately stouter and more carinate ; 

 Pj like P3 ; P, 10 mm. long, resembHng P,, but somewhat more strongly carinate 

 proximally ; following pinnules gradually decreasing to 7 mm. in length and 

 lo.sing the basal carination, then increasing to 12 mm. distally. On some arms 

 Pj is small as described for P,, and again P,^ may also be small, while occasionally 

 Pj and P^ are similar and P.^ is greatly enlarged ; sometimes PP.j, ,, and ^ are 

 as described for PP,, ^, and ,. On one or more of the inner arms of each ray 



