NO. 1561. NEW UNSTALKED CRINOIDS— CLARK. 131 



of such a character as to ahnost appear syzygial, and the two joints 

 are entirely incapable of motion on one another; but the articulation 

 between the first and second radials admits of a very considerable 

 dorso-ventral motion. Judging from Dr. P. H. Carpenter's figure of 

 Atelecrinus halanoides, a similar condition appears to occur in that 

 species. Distichals two, resembling the two outer radials, but higher 

 in proportion to their width; 20 arms (K) mm. in length with about 75 

 brachials, quadrate proximally, becoming triangular, about as high as 

 wide, about the tenth or eleventh. The longer edges of all the 

 brachials are convex and ])ear a pinnule in the center. The second 

 brachial is considerably swollen on the side bearing the pinnule. 

 Syzygies occurs in the third brachial, again about the tenth or twelfth, 

 and distally at intervals of 2, sometimes 3, joints. 



First pinnule short and very slender, iiexilde, with 19 joints, the 

 first two enormously expanded, the remainder very small and squar- 

 ish; second pinnule usually more than twice its length, stiff, stout, and 

 rod-like, with 15-20 joints, the first two much expanded, the remainder 

 elongate. The length of the second pinnule is very variable even in a 

 single specimen; the second pinnule on one arm may be half as long 

 again as that on another, or one of the second pair may be much longer 

 and stouter than its fellow; however, the second pinnule is alwaj^s 

 much longer than the first, and always stifle and spine-like, while the 

 first is weak and flexible. The third pinnule is usually considerabl}- 

 smaller than the second, though similar in character, and from theiv 

 on the length gradualh^ diminishes to the seventh or eighth, after 

 which they remain very uniform to the ends of the arms. The 

 enlargement of the two lower joints, which is greath^ exaggerated on 

 the first pinnule, is much less marked on the second, still less on the 

 third, and hardly noticeable after the fourth. 



The color in life is usually a delicate light graj'ish purple, or lavender, 

 with narrow bands of dull yellow on the arms; one specimen, however, 

 is pure white, the arms crossed by a broad, deep purple band near the 

 middle and another near the tip. The cirri are light lavender, usually 

 with a narrow band of yellow about the end of each joint. 



This small group, of which A. )ni(ltir(>h>r\s the type, illustrates better 

 than any other with which I am acquainted in life the utter worthless- 

 ness of color as a specific character among many of the unstalked 

 crinoids. All but one of my specimens were lavender, narrowl}^ banded 

 with dull yellow; this is the color of all my examples of A. Jiavopur- 

 furea except three, which are a beautiful orange yellow, becoming 

 bright orange on the rays and centro-dorsal; it is also the color of 

 A. dellmtissiiiia of the Palmata group, most closely related to A. 

 limaculata Carpenter, which is dark purple up to the last axillar}^ then 

 white; but this last type of coloration also occurs in ^1. manca { — A. 

 disciforinis— A. elarx), a species widely difl'erent from A. hmiaculata 



