A MONOGRAPH OP THE EXISTING CRINOIDS 615 



In 1921 Doctor Clark wrote that in the Siboga report I assigned this species to 

 the synonymy of Comantheria briareus, in spite of his definite assertion to the con- 

 trary. He said that of course, in view of this action, he had again been over the 

 evidence, and he is confident that I am wrong. 



He noted that the Museum of Comparative Zoology has a fine series of 28 

 specimens of briareus from the Philippines, most of which are accompanied by 

 Doctor Griffin's valuable notes on their color in life. Some of these are rather small, 

 and on one several cirri are present. The presence of cirri in callipepla is not in 

 itself, therefore, a character to distinguish the species invariably from briareus. 

 Indeed, it is quite possible that the Murray Island species may lack cirri when old, 

 and particularly when senescent. 



But comparison of a cirrus of briareus with one of callipepla brings out another 

 distinguishing character not emphasized in the original description. In briareus 

 the cirri when present are composed of about 11 segments and end in a conspicuous 

 curved claw, while in callipepla there are 16 segments and the terminal claw is minute 

 and scarcely at all curved. The form of the individual segments in the two species 

 is also seen to be markedly different when the cirri are placed side by side. 



Doctor Clark remarked that the difference between briareus and callipepla in 

 the form of the IBr and IIBr series is very striking, and by itself is ample to separate 

 them. 



He said that as for the difference in color, briareus is commonly brown of some 

 shade, or very deep reddish; it is often sprinkled, speckled, blotched, or variegated 

 with yellow green or yellow, but in none of the Philippine specimens nor in any 

 recorded cases is there any approach to the green and yellowish-white coloration of 

 callipepla. 



Doctor Clark continued that since examining the holotype (M. C. Z., 579) I 

 decided that callipepla is synonymous with timorensis, an opinion in which he can 

 not possibly concur. Among hundreds of timorensis seen at Mer the maximum number 

 of arms noted was 47, and the largest number which he has found recorded is 68. 

 Moreover, the coloration of callipepla is quite different from that of any of the multi- 

 tudinous color forms of timorensis. Finally, the IIIBr series is 2, not 4 (3 + 4), and 

 hence by my own system of generic division callipepla is a Comantheria and not a 

 Comanthus at all. He was glad, however, that I am ready to admit that it is not 

 briareus. 



In his discussion of timorensis as he found it at Mer, Dr. H. L. Clark said that 

 one form is so sharply set off from the others that it is entitled to designation by a 

 varietal name and may be called variety xanthum. In it the dorsal surface is deep 

 canary yellow, while the pinnules are bright red. He found only 3 specimens with 

 this type of coloration, all near the edge of the reef. He noted that except for their 

 color they were not peculiar. I examined all 3 specimens at Cambridge. As pre- 

 served they do not differ in any respect from typical timorensis. One has 34 arms, with 

 all the division series beyond the IBr series 4 (3+4), the second is similar, and the 

 third (the holotype, M. C. Z., 569) is young. 



Dr. Hubert Lyman Clark reports that as found at Mer the arm length of timorensis 

 ranged from less than 25 mm. up to approximately 150 mm. The number of arms 



