A MONOGRAPH OF THE EXISTING CRINOIDS 107 



weaker than the pinnules preceding. The following pinnules are similar to Pj. The 

 distal pinnules are 11 mm. long, slender, with 29 segments which are short, scarcely 

 half again as long as broad. 



The color in alcohol is light yellowish, with the dorsal pole of the centrodorsal, 

 except for a central spot, and the articulations dark brown. 



Notes. — The preceding description is based upon the type specimen. A specimen 

 from near the Shell Islands, Darwin, was described by Dr. Hubert Lyman Clark as a 

 new species under the name Petasometra variegata! According to him the centrodorsal 

 is thin discoidal with the broad and slightly concave dorsal pole over 3 mm. in diam- 

 eter. The cirrus sockets are arranged in a single closely crowded marginal row. 



The cirri are about XXIII, 22-25, 11 mm. long, with the distal portion markedly 

 recurved. The cirrus segments are very short and broad proximally but become 

 narrower and even compressed distally, with little change in length. The basal 

 segments are twice as broad as long, but the distal are not much broader than long. 

 The dorsal transverse ridge is present from the second segment onward, but it is never 

 very conspicuous and even the opposing spine may be rather small, though it is usually 

 well marked. 



The radials are concealed. The IBri are well developed but short, about four 

 times as broad as long. The IBrj (axillaries) are also short, the greatest length being 

 scarcely one-third the width, the distal angle rounded, and the anterior sides sUghtly 

 concave. There are seven IIBr 4 (3+4) series, and three IIBr 2 series. Of the 

 IIIBr series, nine are 4 (3+4), one is 2, and one is 5 (4 + 5). The division series are 

 aU rather rugged and stout, more or less in contact, and the IIBr series are a little 

 inclined to be swollen. 



The 31 arms are relatively short and stout; all are more or less damaged, but they 

 were apparently not over 80 mm. long (perhaps 100 mm. in life). The brachials are 

 broad and short, about twice as broad as long, beyond the seventh or eighth becoming 

 wedge-shaped. 



Syzygies occur between brachials 3+4 acd 11 + 12, and distally at intervals of 

 from 6 to 8 brachials (7 to 9 muscular articulations). 



Pd is not more than 10 mm. long, rather stout, with 20-23 segments; the basal 

 segment is large, oblong, broader than long; the second is more nearly square and 

 considerably smaller; the third and following are successively smaller and become 

 cylindrical; their margins are all smooth; the distal portion of the pinnule tapers 

 rapidly to a terete but by no means slender tip. Pi is very similar and scarcely 

 longer. Pj is similar but a trifle smaller and with fewer segments. Pg is distinctly 

 smaller and P^ much smaller and with only about a dozen segments. The pinnules 

 succeeding are small, but soon increase in length and number of segments until 

 distally there are again more than 20 in each pinnule, but they are all small. P. 

 is absent. 



The color in alcohol, is very dark^brown, almost^black, variegated with cream 

 color. Many arms are almost white dorsaUy, at least in the distal half, but not the 

 pinnules. Many cirri are white dorsally and vcntrally, but blackish on the sides. 



In a second specimen taken at the same place and time the cirri are XX, 22-24, 

 short, thick, and strongly recurved. The 19 arms are 70-80 mm. long. Of the nine 

 IIBr series eight are 4 (3+4) and one is 2. The first syzygy is between brachials 



