NEW UNSTALKED CRINOIDS CLARK 249 



The cirri are XLV-LX, 11-12, 7 or 8 mm long. The first segment 

 is half again to twice as broad as long; the second is nearly twice as 

 long as broad ; the third and fourth are nearly three times as long as 

 the median width, slightly constricted centrally; and those following 

 slowly decrease in length so that the antepenultimate is not quite twice 

 so long as broad, at the same time losing the median constriction so 

 that they appear slightly broader in lateral view. The penultimate 

 segment is half again as long as broad. The opposing spine is small, 

 terminal, and directed obliquely forward; its dorsal profile makes 

 practically a straight line with that of the penultimate segment. 

 The terminal claw is about as long as the penultimate segment, 

 rather stout at the base, evenly tapering, and evenly and strongly 

 curved. 



The distal edges of the radials are even with the rim of the centro- 

 dorsal. The IBri are extremely short, about six times as broad as 

 long in the median Une, just in contact basally, with the lateral edges 

 so strongly convergent as to make almost a straight line with those 

 of their neighbors. The IBrj (axillaries) are triangular, broader than 

 long, the anterior angle, which is not produced, approximately a right 

 angle, the anterior sides only slightly concave, the lateral angles 

 extending far beyond the anterolateral angles of the IBri, yet widely 

 separated from those of the adjacent axillaries, and with a slight well- 

 rounded process in the median portion of the proximal border. 



The 10 arms are 55 to 75 mm in length. The first brachials are 

 very short, twice as long exteriorly as interiorly, with the proximal 

 half of the inner edges of those of each arm pair in contact and the 

 distal halves diverging at first in a straight Une, which later turns 

 abruptly upward in a sHghtly rounded right angle. The second 

 brachial is much larger and is irregularly quadrate. The first syzygial 

 pair (formed of the third and fourth brachials) is sHghtly longer 

 interiorly than exteriorly, and about as broad as the median length. 

 The next five brachials are almost oblong, and about half again as 

 broad as long. The following brachials become almost or quite 

 triangular, about as long as broad, and gradually wedge-shaped and 

 elongate distally. The distal edges of the brachials are slightly 

 produced and finely spinous, giving the profile of the arm a regularly 

 serrate appearance. 



Syzygies occur between brachials 3+4, 9 + 10, and 14 + 15, and 

 distally at intervals of 2 (rarely 3) muscular articulations. 



In the type specimen Pi is 10 mm long with 20+ segments, slender 

 but not attenuated; the first segment is short, the second is about as 

 long as broad, the fourth and fifth are twice as long as broad, and the 

 distal are about four times as long as broad. The elongated segments 

 have somewhat abruptly produced and overlapping distal ends, 

 which are armed with very fine spines. P2 is 8 mm in length with 13 



