82 Clark — Neiv Recent Crinoids from the Indian Ocean. 



Centro-dorsal a short truncated cone, moderately large, the bare polar 

 area flat, 2.5 mm. in diameter; cirru.s sockets arranged in ten colunms of 

 usually two each, the columns of adjacent radial areas closely crowded and 

 more or less alternating, those within the same radial area usually slightly 

 separated anteriorly. 



Cirri xx, 21-22, 25 mm. to 36 mm. long, comparatively long and slender ; 

 first joint very short, second twice as broad as long, third about as long as 

 broad, following gradually increasing to the sixth, which is about half 

 again as long as broad ; next two or three joints similar, the following very 

 gradually decreasing in length, those in the terminal third of the cirrus 

 being about as long as broad ; antepenultimate joint about one-third longer 

 than l)road; penultimate joint half again as long as broad, slightly less 

 in diameter than the preceding; opposing spine very small, though promi- 

 nent, terminally situated, directed obliquely forward ; terminal claw about 

 as long as the penultimate joint, stout basally, becoming slender in the 

 distal half, moderately curved. The cirri are moderately compressed in 

 the distal two-thirds ; the two or three joints before the penultimate have 

 slight traces of terminal dorsal tubercles. 



Disk covered witli a j^avement of very small plates; side and covering 

 plates well developed along the ambulacra. 



Ends of the basal rays visible as large rhombic tubercles in the angles 

 of the calyx; radials only visible as a large transversely oblong tubercle 

 between the centro-dorsal and the i Bri ; i Bri very short, arcuate, in 

 close lateral apjiosition, the proximal edge more or less crenulate, and 

 bearing a large and rather high transversely oval median tubercle; i Bro 

 (axillary) rhombic, very short, somewhat over twice as broad as long, 

 the edges somewhat crenulate and somewhat produced, the proximal 

 imbricating more or less over the anterior border of tlie i Bri ; the lateral 

 edges are very short, in close apposition; it bears a rather large and high 

 roiinded median tubercle; ii Br 4 (3 -1- 4) iii close lateral apposition and 

 sharply flattened, with the lateral edges slightly everted; the distal edge 

 of II Bri is somewhat everted, and the proximal edge of ii Br2more strongly 

 everted, the latter imbricating slightly over the former except in the 

 median line; ii Bn usually bears a strong rounded median tubercle like 

 that on the two components of the i Br series. 



Thirteen arms (in the type) 170mm. long, elongated and comparatively 

 slender, resembling those of P. robu8ta. 



The pinnules in general resemble those of P. robuala, but the pinnules 

 in the proximal part of the arm are strongly carinate. 



Pachylometra investigatoris sp. nov. 



Tjipe. — Cat. No. 13A = "*',;"" Indian Museum; Malay Archipelago, 30 

 fathoms. 



Centro-dorsal a truncated cone, 7 mm. broad at the base and 5 mm. 

 high, the cirrus sockets arranged in two columns of three to five each in 

 each radial area, the two columns of each area separated by a narrow 

 median line not quite so broad basally as the cirrus sockets, distally 

 narrowing and ending in a point at about the level of the third or fourth 



