A MONOGRAPH OF THE EXISTING CRINOIDS 273 



less complete second row and in 15 columns, 3 in each radial area, the middle column 

 in each radial area consisting of a single cirrus near the dorsal pole. In the Misaki 

 specimen there are 10 cirri about the proximal rim of the centrodorsal, 7 of these having 

 another just beneath it, and 5 smaller ones midradial in position about the dorsal pole. 



The cirri are XV-XXII, 15-18, up to 25 mm. in length. The first segment is short, 

 those following increasing in length to the sixth and seventh, which are from slightly 

 longer than broad to about one- third again as long as broad, thence remaining uniform, 

 or slowly decreasing to about as long as broad or, in the stoutest cirri, even slightly 

 broader than long, toward the tip. The segments beyond the basal portion are very 

 slightly flaring, and those in the distal third of the cirri have a slight well rounded tuber- 

 cle dorsally at the distal end. The opposing spine is well developed, conical, stout, and 

 blunt, terminal, and leaning slightly forward. The terminal claw is about as long as 

 the penultimate segment, moderately stout, tapering more rapidly in the proximal 

 third than distally, and moderately curved, most strongly in the basal third. 



The ends of the basal rays are visible as dorsoventrally elongate tubercles in the 

 angles of the calyx. 



The radials are concealed or more or less of them may be visible beyond the rim of 

 the centrodorsal. The IBri are very short, bandlike, broadly V-shaped, with more or 

 less coarsely crenulate edges and a central more or less circular low tubercle. The 

 IBr 2 (axillaries) are rhombic, more than twice as broad as long, with the lateral angles 

 truncated and the lateral borders slightly everted. The distal sides are rather strongly 

 concave and there is a median tubercle narrower than that on the IBri and dorsoven- 

 trally elongate in the proximal two-thirds. The elements of the IBr series and the 

 first two brachials are closely appressed and sharply flattened laterally. 



The 10 arms are 115-130 mm. long. The two first brachials are somewhat wedge- 

 shaped, longer exteriorly than interiorly, the second rather larger than the first. They 

 have a low and rather narrow raised median line and slightly everted borders. The 

 first syzygial pair (composed of brachials 3+4) is oblong, about twice as broad as long; 

 each element has a low median rounded tubercle, or the hypozygal may have a row of 

 4 or 5 small low rounded tubercles. The twelfth brachial is regularly oblong. The 

 brachials between the first syzygial pair and the twelfth are slightly wedge-shaped, 

 more than twice as broad as long with an uneven surface though not tubercular. After 

 the twelfth the brachials become triangular, slightly broader than long, soon becoming 

 about as long as broad. The lower triangular brachials have each an obsolescent median 

 rounded tubercle. The distal ends of the brachials may be slightly produced, this 

 condition, if present, tending to become more accentuated distally. 



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

 distally at intervals of from 8 to 1 1 muscular articulations. 



P, is 10 mm. long, comparatively slender and tapering rather gradually from the 

 base to the tip, and is composed of about 40 short segments of which the basal 8 or 

 10 are flattened exteriorly and rather broad. P 2 is much shorter than Pi with about 23 

 segments of which the proximal 8 or 9 are much expanded laterally. P 3 resembles 

 P 2 but is somewhat shorter and the 6 basal segments are even more expanded, reaching 

 a maximum on the third and fourth, thence tapering to the tip. The following pin- 

 nules to about the fiftieth brachial are similar, but the number of segments increases 

 from 12 on P 4 to 20 on the pinnule of the fiftieth brachial; as the great lateral expansion 



