A MONOGRAPH OF THE EXISTING CRINOIDS 343 



twice as broad as long. The antepenultimate segment is about as long as broad. 

 The penultimate segment is very small, usually about half as long as the antepenulti- 

 mate and nearly or quite twice as broad as long. The cirri are perfectly smooth 

 dorsally and ventrally; they are rounded in cross section in the proximal half, but 

 become laterally flattened in the distal half, and therefore here considerably broader 

 in lateral view. The opposing spine is small and blunt, often quite absent, median 

 to subterminal in position. The terminal claw is stout basally, but tapers rapidly; 

 it is about as long as the antepenultimate segment and is strongly curved basally, 

 becoming straighter distally. 



The ends of the basal rays are visible as minute tubercles in the angles of the 

 calyx. 



The radials are entirely concealed by the ccntrodorsal, or can just be made out 

 in the interradial angles of the calyx over the ends of the basal rays. The IBr] are 

 very short, bandlike, with the distal edge straight and the proximal somewhat convex 

 with a prominent median groove or furrow. The IBr 2 (axillaries) are broadly tri- 

 angular, twice as broad as long. The IBr series and the first 2 brachials are in close 

 lateral contact. 



The 10 arms are about 130 mm. in length. The first brachials are small and 

 short, very slightly wedge-shaped. The second brachials are somewhat larger and 

 very obliquely wedge-shaped. Both the first and second brachials are in contact 

 interiorly. The distal edge of the second brachials is parallel to the outer edge of 

 the radials. The third brachials are exceedingly short and oblong. The fourth 

 are almost twice as long and triangular with the apex near the interior side. The 

 next 4 brachials are slightly wedge-shaped, very short, three or four times as broad 

 as long, and with the articular tubercles strongly developed. The succeeding 

 brachials become triangular, about twice as broad as long, with the distal edge 

 concave, very gradually increasing in length distally and in the outer part of the arm 

 being very obliquely wedge-shaped and nearly as long as broad. The arms gradually 

 increase in diameter from the base to the twelfth-twentieth brachials, thence grad- 

 ually decreasing in width distally. The distal ends of the brachials are prominent, 

 though not overlapping. The brachials in the proximal portion of the arm appear 

 swollen, this feature becoming less and less marked distally. 



Syzygies occur between brachials 1+2 and 2 + 3, often also 3 + 4, again between 

 brachials 11 + 12 or 12 + 13, and thence at intervals of usually 6 (sometimes as few 

 as 4) muscular articulations. 



Notes. The specimen from the China Sea recorded by Hartlaub resembles in 

 its general habitus the two from Cooktown, Queensland. 



The specimen from Albatross station 5276 is a fine example with only VI rather 

 short and slender cirri which are irregularly distributed about the circumference of 

 the centrodorsal, not being segregated in the interradial angles like the cirri of 

 C. purpurea. 



In the two examples from Sorsogon, Luzon, the anterior arms are about 125 mm. 

 in length. 



In the specimens collected by Semper at Bohol, Pi and the following pinnules 

 have keels on the basal segments and much less massive brachials and pinnule 

 segments than C. Solaris. 



