226 SMITHSONIAN MISCELLANliOUS COtLECTIOXS VOL. 5^ 



tally, the brachials developing prominent overlapping spines, as in 

 P. macronema. Syzygies occur between the third and fourth brach- 

 ials (in one case the first syzygy is betv^^een the sixth and seventh), 

 again between the thirteenth and fourteenth to nineteenth and twen- 

 tieth (most commonly between the seventeenth and eighteenth, with 

 rarely an additional syzygy between the seventh and eighth), and 

 distally at intervals of six to twelve (usually seven or eight) oblique 

 muscular articulations. 



First pinnule small and weak, about 6.5 mm. long, with 10 or 12 

 joints, the first short, the second rather longer than its anterior diam- 

 eter, decreasing in width distally, the remainder about two and one- 

 half times as long as broad ; second pinnule about 9 mm. long, stiff 

 and spine-like, with fifteen joints, the first short, the second rather 

 longer than its anterior diameter, the third not quite so long as 

 broad, the following about twice as long as broad; the pinnule is 

 sharply triangular, and the dorsal ridge on each joint is produced 

 distally over the bases of the succeeding joints in the form of a 

 slender spine ; third and following pinnules similar to the second, but 

 about 10 mm. long. The pinnules as a whole are considerably more 

 delicate than are those of P. macronema ; the plating of the disk and 

 ambulacra is approximately as in P. macronema. 



Measurements. — Arms 70 mm., cirri 60 mm. in length. 



Color (in spirits). — White, the costals with a lateral line, the 

 division-series with narrow transverse lines at the articulations, and 

 the pinnules with a spot in the middle of each joint of very light 

 purple; cirri deep violet in the distal two-thirds, in the proximal 

 third white, with a lateral line of deep violet. 



Another specimen is entirely deep purple. 



Type. — Cat. No. 25447, U. S. N. M., from Albatross Station No. 

 5153; east of Port Dos Amigos, Tawi Tawi ; 49 fathoms. 



This species was also found at Station No. 5179; between Tablas 

 and Romblon ; 37 fathoms. 



The large number of arms, the narrowness of the calyx and arm 

 bases, the extraordinary spinous ventral overlap of the joints in the 

 proximal third of the cirri, the regular arrangement of the cirri, and 

 the greater delicacy of the entire animal distinguish this species at 

 once from P. macronema. The number of arms alone is usually a 

 sufficient character, for, although sometimes having as many as 

 thirtv. P. macronema usuallv has less than twentv. 



