iSi 
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 two 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 C.\rpenter'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. Cl.\RK. Proc. Biol. Soc. Washington, vol. 22, 1909, p. 81 [Pacliyloinetra mactlenta). 
Crinoids of the Indian Ocean, 1912, p. 222, fig. 41, p. 223 {Pacliyloinetra macilenta). 
7. Perissometra iiivemista (A. H. Clark). 
A. H. Cl.-vrk. Proc. Biol. Soc. Washington, vol. 22, 1909, p. 149 [Pachylovietra 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° 29.2 S., 1 32° 52. 5 E. 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 crowded interradially, slightly separated 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 
beine slicrhtlv shorter aeain ; on the seventh a slicjht 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 IBr, 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 longr, rhombic, the lateral angles truncated so that the lateral sides 
are nearly or quite as long as those of the IBrj. 
The arms are 10 or 11 in number, about 180 mm. long; the IIBr series are 4 (3 + 4); 
the first two brachials are about equal in size, slightly wedge-shaped (more pronouncedly so 
