A MONOGRAPH OF THE EXISTING CRINOIDS 617 



The radials are visible. The IBr ( are very broad and are in lateral contact. 

 The IBr 2 are very broad also. The IIBr and IIIBr series are 4 (3+4). 



The 40 arms are nearly or quite 100 mm. long. The first brachials are broad 

 and are in contact interiorly. After the sixth the wedge shape of the brachials 

 rapidly becomes apparent, and the segments strongly overlap on either side alter- 

 nately. The distal edges of the brachials may present delicate denticulations. 

 Some way out the wedge form diminishes, and then, owing to the strong projec- 

 tion of the ridges, the arms appear somewhat as though they were ringed. 



Syzygies occur between brachials 3+4, 11 + 12, and 16 + 17, and distally at 

 intervals of about 5 muscular articulations. 



The pinnule on the IIIBr series is only a very little longer than P D ; both are 

 made up of a large number of small segments. The fourth or fifth pinnule is short 

 and fleshy. Further out the pinnules are longer again, and their segments are elon- 

 gated and delicate. 



The disk is 10 mm. in diameter. 



The type material on which the name annulata is based consists of 4 specimens. 

 One of these has 40 arms and VIII cirri, these being deficient on a part of the periphery 

 of the centrodorsal. Another has 39 arms and IX cirri, which are absent from a 

 part of the periphery of the centrodorsal. A third has 39 arms and the cirri XII, 

 16-17. One of the IIBr series is 2, but the other IIBr series and all of the IIIBr 

 series are 4 (3 + 4). The fourth specimen is broken. 



A comparison between the characters of these specimens and Bell's descriptions 

 shows that the third is the one which he must have had chiefly in mind when he 

 wrote the diagnosis, as it is the one which has the cirri nearest the number given by 

 him. It should therefore be considered as the type, and indeed was designated as 

 the type in my memoir on the crinoids of the Indian Ocean (1912). 



According to Dr. H. L. Clark, the specimen from Surprise Shoal is small with 

 21 arms between 40 and 50 mm. in length, and IV cirri. 



The specimen recorded by McNeill and Livingstone from off Ellison Reef is 

 juvenile, with the longest arms measuring about 72 mm. The ventral side is dark 

 brown, the dorsal side lighter. 



Of the 2 immature specimens from Port Denison in the Australian Museum, 1 

 has 19 arms about 100 mm. in length, and the other has 24 arms about 120 mm. long. 

 In both the centrodorsal is much reduced in size. 



In the specimen from Bowen in the Copenhagen Museum the centrodorsal is a 

 very thin pentagonal plate which is scarcely raised above the dorsal surface of the 

 radial pentagon. Three of the basal segments of a single cirrus remain. 



The division series are broad and are in close lateral apposition to and including 

 the IIBri, but are well separated from that point onward. The IIBr series, IIIBr 

 series, and IVBr series, of which last 5 are present, are 4 (3 + 4) except for a single 

 IIBr series and 3 IIIBr series, which are 2. 



The 45 arms are 195 mm. long. The brachials are short triangular or wedge- 

 shaped, over twice as broad as long, with everted distal ends. 



