A MONOCJRAPH OF THE EXISTING CRINOIDS 241 



COMANTHOIDES SPANOSCHISTUM (H. L. Clark) 



(Plate 21, Figures 52-57; Plate 22, Figure 58; Plate 23, Figure 63) 



Comanihus spanoschistum H. L. Clark, Biol. Results Fishing Exper. F. I. S. Endeavour, 1909-1914. 

 vol. 4, pt. 1, 1916, p. 17 (description; notes and comparisons; localities); pi. 4, fig. 3 (holotype; 

 east of Flinders I., 100-300 fathoms). — A. H. Clark, Proc. Biol. Soc. Washington, vol. 31, 

 1918, p. 41 (lO-armed specimens referred to Comissia); p. 42 (specimens with more than 10 

 arms considered synonymous with Comanthus tasmaniae) . 



Comissia spanoschistum A. H. Clark, Proc. Biol. Soc. Washington, vol. 31, 1918, p. 41 (listed from 

 Tasmania); p. 42 (discussion). 



Comanthus tasmaniae (part) A. H. Clark, Proc. Biol. Soc. Washington, vol. 31, 1918, p. 42 (speci- 

 mens with more than 10 arms referred to this species). 



Description. — According to Dr. H. L. Clark, the centrodorsal is large and flat, 

 in adults 5 mm. in diameter and about 1 mm. thick. The cirri are arranged in one 

 and a partial second marginal rows. 



The cirri are about XXIV, 15-20, the longest from 10 to 15 mm. in length. 

 The fourth-seventh or third-eighth segments are cylindrical and are longer than 

 broad; the fourth (or fifth) maj'^ be nearly twice as long as broad. Distally the 

 segments are a trifle compressed, and the distal margin dorsallj^ is elevated to form 

 a low tubercle which, at least on the penultimate segment, is spiniform. 



The radials are concealed. The IBrj are low and broad, more or less in contact 

 laterally. The IBr2 (axillaries) are triangular, high and pointed, half again as broad 

 as long. The IBr series, when present, are 4 (3+4). There are no IIIBr series. 



The arms are 10-19 in number, but usually 10. In the type series of 23 speci- 

 mens one had 13, another 14, and a third 19 arms, the remaining 20 having 10 arms. 

 The arms are from 30 to 80 mm. long. The brachials are at first quadrilateral, but 

 soon become triangular. Their distal edges become more and more produced and 

 overlapping until near the tips of the arms, where the brachials become quadrilateral 

 again and the distal edges are scarcely produced. 



Syzygies occur between brachials 3+4, and then at an interval of from 7 to 11 

 muscular articulations. After that the intersyzygial interval is usually 5, but may 

 be only 3, muscular articulations. 



The pinnules are long and slender. Pi is over 10 mm. long and consists of about 

 30 segments, of which about 15 are involved in the formation of the comb. Pj is some- 

 what smaller, and P3 is only 8 mm. long and is composed of 20 segments, of which 

 9 are involved in the formation of the comb. P4 is 8 mm. long and is without a comb. 

 The succeeding pinnules become more slender and increase in length to about 10 mm. 

 The basal segments of the lower pinnules are more or less triangular with greatl3" 

 flaring spinulose margins which tend to project like rough spurs on the aboral side 

 of the largest segments. 



The disk is from 5 to 12 mm. in diameter, and except around the tip of the anal 

 tube is smooth and naked. There are calcareous nodules on the anal tube. The 

 mouth is interradial. 



The color, both in alcohol and dry, is more or less yellowish, with either a green 

 or a brown cast. One specimen is very dull purplish with yellow cirri; others are 

 yellowish, more or less clouded with purplish; in the 19-armed individual the dull 

 purplish predominates. 



