PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 467 



mcnts and measuring 8-9 mm. in length. The arms are all broken. The IBr, is 

 one third as long as wndc and the axillary four fifths as long as wide. Syzygies occur 

 at brachials 3 + 4, 11 + 12, and 18+19, distally at intervals of from 5 to 17 muscular 

 articulations. Pi has 11 segments and measures 6.5 mm. Pj has 10 segments and 

 measures 6 mm. P3 with 10 segments measures 5.2 mm. All the pinnulars are smooth. 

 P» is present. 



The second specimen has XXIII cirri with 27-36 segments and measuring S-11 

 mm. in length. The arms are about 35 mm. long, but broken. The syzygial interval 

 is 4 to 5 muscular articulations. Pi wdth 9 segments is 4.3 mm. long. Pj with 10 

 is 3.2 mm. long. P3 has 9 segments and measures 3.5 mm. P^ is present. 



One of these has a rather stout synarthrial tubercle on the IBr series but in the 

 other it is much less developed. 



Gisl6n also comments that the young of this species can be distinguished from 

 those of Erythrometra rubra (with which it occurs) by the more distinct dorsal spines 

 of the cirrus segments, the closer arm bases, the absence of granules in the skin of the 

 disk and the smooth pro.ximal pinnules. 



Young individuals of this species are very dififerent in appearance from the fidly 

 grown. They have fewer cirri with somewhat fewer segments, the brachials are all 

 more or less elongated, and there are no traces of the characteristic exaggerated syn- 

 arthrial tubercles, though their future location is indicated by purple spots. On the 

 basal portion of the arms there is a light purple median line fading into white distally. 



^Vhen an arm length of about 30 mm. is reached, the sj-narthrial tubercles begin 

 to appear, rapidly increasing in size and becoming quite e\'ident at an arm length of 

 about 40 mm., and reaching the full size at the latest when the arm length has reached 

 45 mm. With the development of the synarthrial tubercles, the median purple lines 

 on the arms gradually disappear, giving place to bands of greater or lesser width, 

 or sometimes large blotches. These are at first light in color and do not become 

 dark until nearly the full size has been attained, when purple bands also appear upon 

 the cirri. 



Most of the specimens of this interesting species so far secured are young, only 

 a very few being sexually mature. The most richly colored individuals are from the 

 least depth, though some others very similar were found at 188 meters. The largest 

 specimens were brought up from J2S to 164 meters. 



Color in life. — In the most richly colored individuals the arms, pinnules and cirri 

 axe a rich reddish purple blotclied and streaked with white, the arm bases and calyx 

 being white with the synartlirial tubercles and a broad band on each of the lower 

 brachials reddish purple. 



More commonly the color is white, with the synarthrial tubercles, narrow bands 

 on the arms and cirri, and blotches on the pinnules purple. 



Abnormal specimens. — In a large and pale individual dredged b}^ Mr. Alan Owston's 

 yacht Golden Hind in Sagami Bay in 155 meters one post-radial series is dwarfed, being 

 about half the size of the others. On this post-radial series the IBr, is lacking, the 

 a.xillary springing directly from the radial without any tubercular elevation of its 

 proximal border. On the left arm there is a partial additional second brachial which 

 is dorsally visible externally from the outer side of the arm to the median line, its length 

 in the direction of the long axis of the arm being about half as great as its width. This 



536-622—67^—31 



