A MONOGRAPH OF THE EXISTING CRINOIDS 539 



Diagnostic features. P 3 is stout, stiff, and rigid, typically conspicuously longer 

 and stouter than P 2 or P 4 , 15-20 mm. long, with 16-25 segments, P 2 being 11-15 mm. 

 long with 17-23 segments; the cirri are XXX, 30-43, 20-35 mm. long, with the seg- 

 ments subequal, all very slightly longer than broad or those in the proximal half 

 slightly longer than broad and those in the distal half slightly broader than long; the 

 distal segments are carinate dorsally, without dorsal tubercles or spines; and the 19-21 

 arms are 70-115 mm. long. 



Description. The cirri are XXX, 30, 20 mm. long. The segments are remark- 

 ably uniform in size, very slightly longer than broad ; there are no dorsal processes or 

 opposing spines. 



The radials are just visible. The IBr, are short, less than half the length of the 

 irregularly rhombic IBr 2 (auxiliaries), and are in close contact laterally. The IIBr 

 series are 2. The IIBrj are oblong, about two and one-half times as broad as long, 

 and the IIBr axillaries are triangular, about twice as broad as long. There is a low 

 synarthrial tubercle on the articulations between the elements of the IBr and IIBr 

 series. The IBr series, IIBr series, and first brachials are hi close lateral contact. 



The 19 arms are 70 mm. long and consist of about 150 brachials, of which the 

 first 8 are oblong, those following as far as the fortieth brachial are triangular, much 

 broader than long, and the remainder are wedge-shaped. The lower brachials aie 

 slightly tubercular, and all the brachials have slightly overlapping distal ends. 



Syzygies occur between brachials 3+4 and at about brachials 13 + 14, and 

 distally at intervals of about five muscular articulations. 



P, 8 mm. long, rather slender, and composed of 16 moderately elongated seg- 

 ments. P 2 11 mm. long, stouter than PI, with 17 segments. P 3 15 mm. long, stout, 

 stiff, and rigid, composed of 16 long cylindrical segments; this pinnule is much stouter 

 and stiffer than any of the others. P 4 10 mm. long. P s 7 mm. long. The distal 

 pinnules are 8 mm. long, tapering gradually from the base to the tip, with about 20 

 segments. 



Notes. In one of the specimens from Sagami Bay (No. 4219) the cirri are 25-35 

 mm. long and composed of 33-43 (usually about 38) segments, which are subequal, 

 about as long as broad, or slightly longer than broad in the proximal half and slightly 

 broader than long in the distal half. The segments in the distal third (or somewhat 

 more) of the cirri are carinate dorsally, but the carination is not produced, so that it 

 is not evident except upon close examination, the outer segments appearing quite 

 smooth. The opposing spine is very small, triangular, with the apex terminal, and 

 arises from the entire dorsal surface of the penultimate segment. The division series 

 and lower brachials are almost in lateral contact, and the lateral edges of the ossicles 

 of the division series are swollen. There are 21 arms about 115 mm. long. All the 

 IIBr series are present, and there is one external IIIBr series. 



P! is 11.5 mm. long, slender and evenly tapering, composed of 23-25 segments, of 

 which the second and third are about as long as broad and most of the remainder are 

 about twice as long as broad. P 2 is 15 mm. long, with 23 segments, similar to PI but 

 stouter and stiffer. P 3 is 20 mm. long, with 25 segments, similar to P 2 but proportion- 

 ately stouter and stiffer. P 4 is 13.5 mm. long, with 20 segments, and is similar to P 2 . 

 P 5 is 10 mm. long, with 19 segments, tapering more rapidly in the proximal third than 

 the preceding pinnules and more slender from that point onward. P 6 and the following 



