Ibl 



being 2 ; all of the arms except three, which are broken, are regenerating. The tubercles on 

 the ossicles of the division series and on the first t\\ r o brachials are not quite so extensive, 

 though slightly more marked ; the proximal and distal borders of these segments except in 

 the median line are slightly produced and slightly scalloped, this increasing progressively to 

 to the margin; the lateral edges are similarly produced and slightly swollen, but nearly straight 

 without tubercular modification ; very narrow transversely elongate slits, scarcely noticeable, 

 mark the position of the future water pores. 



These specimens appear to belong to Carpenter's robusta, though they are more developed 

 than his type. The chief characteristic of the species is the very long and stout cirri. 



6. Perissometra macilenta (A. H. Clark). 



A. H. Clark. Proc. Biol. Soc. Washington, vol. 22, 1909, p. 81 [Pachy lometra macilenta). 

 Crinoids of the Indian Ocean, 191 2, p. 222, fig. 41, p. 223 [Pachy lometra macilenta). 



7. Perissometra invenusta (A. H. Clark). 



A. H. Clark. Proc. Biol. Soc. Washington, vol. 22, 1909, p. 149 {Pachylometra invenusta). 

 Crinoids of the Indian Ocean, 1912, p. 220, fig. 40, p. 221 [Pachylometra invenusta). 



8. Perissometra crassa (A. H. Clark) 



A. H. CLARK. Proc. Biol. Soc. Washington, vol. 25, 1912, p. jj [Pachylometra crassa). 

 Stat. 259. 5°29'.2S., i32°52'.5E. Between Kei Islands. 487 Metres. 2 Ex. 



The centrodorsal is very large, truncated conical, the sides making a rather small angle 

 with each other, 9 mm. in diameter at the base, 5 mm. across the irregularly convex dorsal 

 pole, and 5 mm. high ; the cirrus sockets are arranged in ten columns, usually three to a 

 column, the columns being closely crowcled interradially, slightly separatecl radially. 



The cirri are about XXV, 18 — 22 (usually 20), 25 mm. to 32 mm. long, stout and 

 short segmented ; the first segment is short, the following gradually increasing in length so 

 that the sixth and following are nearly as long as broad, those in the outer third of the cirri 

 being slightly shorter again; on the seventh a slight broad subterminal dorsal hump makes its 

 appearance which slowly increases in height so that the terminal nine possess a prominent 

 broad blunt and well rounded subterminal tubercle which becomes more pointed on the last 

 two or three before the penultimate; the opposing spine is small, subterminal, resembling the 

 tubercle on the preceding segment, but arising from a much smaller base. 



The radials and the ends of the basal rays are concealed; the IBrj are very short, 

 broadly V-shaped, sometimes concealed in the median line so that only the lateral portions are 

 visible ; the dorsal surface is more or less irregular ; the axillaries are short and broad, nearly 

 three times as broad as long, rhombic, the lateral angles truncated so that the lateral sides 

 are nearly or quite as long as those of the IBr r 



The arms are 10 or 11 in number, about 1 So mm. long; the IIBr series are 4 (3 + 4); 

 the first two brachials are about equal in size, slightly wedge-shaped (more pronouncedly so 



