NO. 1820 RECENT CRIXOIDS FROM PHILIPPINES CLARK 225 



increasing in length to the fifth, which is squarish, and still further 

 nicreasing to the eighth, which is not quite half again as long as 

 broad; the proportions of the following joints similar until the 

 eighteenth or twentieth, after which the joints gradually decrease in 

 length, the thirty-second to the thirty-fifth being squarish, the follow- 

 ing gradually becoming broader than long, the terminal joints being 

 very short; the fourth to about the sixteenth joints with a strong, 

 ventral overlap (though smooth dorsally), and the middle of the 

 distal ventral border strongly produced in the form of a sharp and 

 prominent spine, this condition reaching a maximum on the eighth 

 or ninth joint, then gradually decreasing in intensity, disappearing 

 after about the sixteenth ; at about the twenty-fifth joint a slight 

 prominence of the distal dorsal edge is noticeable ; after the thirty- 

 sixth the median part of the dorsal edge is produced into a small, 

 sharp spine which projects forward in line with the rest of the dorsal 

 surface of the joint ; after about the fiftieth joint this spine begins 

 to broaden basally, soon transforming into a high curved spine 

 arising from the entire dorsal surface of the joints, just like the 

 dorsal spines in the distal part of the cirri of P. niacronenia; last 

 ionr joints decreasing rapidh' in size; opposing spine very small 

 (though of normal proportions when compared to the very small 

 penultimate joint which bears it) ; terminal claw minute. 



Ends of basal rays visible as dorso-ventrally elongated tubercles 

 in the angles of the calyx ; radials rather prominent, about four times 

 as broad as long, with a rather low, rounded tubercle in the median 

 part of their proximal border, first costals oblong, about three times 

 as broad as long, in close lateral apposition and somewhat flattened 

 laterally ; costal axillaries rhombic, about twice as broad as long, 

 with a tendency to rise into a low, rounded tubercle at the articula- 

 tion with the first costals ; distichals and palmars 2, the latter devel- 

 oped exteriorly in 2, i, i, 2 order; division-series and first four or 

 five brachials sharply "wall-sided ;" but, owing to the thinness of the 

 joints dorso-ventrally, the flattened lateral area is comparatively nar- 

 row. Twenty-four to thirty arms ; first eight brachials discoidal or 

 oblong, about twice as broad as long, then gradually becoming more 

 and more wedge-shaped, and after the twelfth obliquely wedge- 

 shaped, not quite so long as broad, and in the distal portion of the 

 arms less obliquely wedge-shaped again, but not increasing in length ; 

 arm ending abruptly with a few minute incurved joints, as in P. 

 inaci'oncma, the terminal pinnules exceeding the arm tip by about 

 4 mm. ; arms dorsally rounded and comparatively broad in the prox- 

 imal half, becoming gradually strongly compressed and carinate dis- 



