NO. 1561. NEW UNSTALKED CRINOWS— CLARK. 143 



i6. ANTEDON ORION, new species. 



Centro-dorsal a tliick disk, bearing- 9-25 (usually about 12-15) 

 smooth cirri, irregularly disposed in one or two rows about the mar- 

 gin. The cirri are 20 mm. long, with 15-25 joints, the distal bearing 

 low spines. The cirri are of peculiar shape; the tirst 5-7 joints are 

 large and stout, rounded, the first 3 very short and wide, the others 

 longer than wide; the remaining- joints are conspicuously less in diam- 

 eter, compressed, and short; moreover, the stout basal joints are dull 

 greenish in color, and have a dull surface; the slender distal joints are 

 light yellow in color, with a highly polished surface; the transition 

 takes place on a joint shaped like a truncated cone, the distal portion 

 encircled b}^ a raised and highly polished collar; this joint is usually 

 darker in color than those preceding- it, and, like them, has a dull 

 surface, except for the terminal collar. In most cases it is very 

 conspicuous. 



The disk is moderately but sometimes rather scantily plated; the 

 ambulacra are always well plated. 



First radials usually concealed; second radials short and bandlike, 

 bluntly carinate, the edg-es rough; axillaries triangular or widely pen- 

 tagonal, always much Vvdder than high, the surface rugose. Distichals 

 two, the first very short, the axillary about as wide as high, almost 

 triangular. Ten to eighteen arms, 110 mm. long; first brachials very 

 short and bandlike; the succeeding brachials to the tenth or twelfth 

 irregularly oblong or slightly quadrate, short, and slightl}" tubercu- 

 lar; following brachials more distinctly quadrate, soon becoming tri- 

 angular, the distal edges abruptl}^ turned outward, this condition 

 becoming marked after the tenth, at which point projections in the 

 produced distal edge on alternate sides of the arm begin to appear, 

 which distally draw nearer and nearer in the median line, resulting, 

 after the thirtieth brachial, in a strong median carination, produced 

 distally into overlapping spines, resembling those in Anfedon (juinque- 

 costata; after the thirtieth brachial, too, the arms, which heretofore 

 have been rounded dorsally , become laterally compressed, the diameter 

 decreasing rather suddenly and the arms becoming- narrow. 



First pinnule the longest, 6.5 mm. long, with 16 short scpiarish 

 joints, somewhat flattened on the outer side, the basal stout, the distal 

 tapering gradually; second pinnule like the first, but slightly shorter; 

 following pinnules decreasing in length to about the sixth, which is 

 4 mm. long, with 9 joints, all rather broad except the last two; distally 

 the length increases graduall}" to T or 8 mm., with 18 squarish joints, 

 tapering gradually from the base. All the pinnules are strongly 

 carinate. 



Color in life bright yellow, usually banded rather narrowly with 

 white; cirri dull greenish basally, light yellow distally, the colors 



