196 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



i ho proximal portions of the Bhort IBr, which have lateral extensions meeting those 

 of their fellows on either side. The IBr.. (axillaries) are pentagonal, quite free laterally, 

 and rather more than twice as long as the IBr,, with moderately sharp distal angles. 

 The post-radial series may divide three times. Six of the lIBr series are 4(3+4) and 

 three are 2; the remaining one is broken away. The IIIBr series, when present, are 

 4(3 + 4). The first ossicles beyond each axillary are closely united laterally. The 

 total diameter between IIIBr axillaries is 25 mm. 



There are 17+ arms. The pinnules borne by the second ossicles after each 

 axillary are enormously large and stout, so much so that the ossicles bearing them 

 have almost the appearance of being axillaries themselves. Each pinnule contains 

 20+ massive segments the ventral edges of which are produced so as to stand up as 

 plates sloping slightly inward toward the ambulacra! groove. The disk is lost. 

 The diameter of the centrodorsal is 7 mm. The color is light brownish white. 



( Jarpenter said that, although no traces remain either of the disk or of a terminal 

 comb on the oral pinnules, the flattened calyx and the wide funnel in the center of the 

 radial pentagon indicate the generic position of this specimen, which is markedly 

 different from most species of Actinometra that he had seen. 



I examined the type specimen of Carpenter's Actinometra robustipinna at Leyden 

 in 1 '.HO, and in 1911 I wrote that it proved to be a specimen of a typical species of 

 lliuurometra. All the IIIBr series are 4(3+4). The proximal pinnules are very 

 large and stout, the tips ending bluntly after a considerable recurve. So far as they 

 are preserved the segments are broader than long. The distal ends are not thickened 

 or produced, though appearing slightly prominent and a trifle swollen. One P 3 with 

 IS segments appears to be complete. 



The three specimens collected by Dr. J. Brock at Amboina were described by 

 llartlaub as a new species, Antcdon crassipinna, in the following terms: The centro- 

 dorsal is broad and thick, rather deeply concave in the middle; the cirri are arranged 

 in three marginal rows. The cirri are about XXXVII, 30^0, reaching 46 mm. in 

 length. None of the segments are longer than broad. Toward the ends the cirri 

 become compressed laterally and the outermost segments bear small spines. The 

 radials are entirely concealed, or only in small part visible. The IBr, are partially 

 united laterally. The IBr 2 (axillaries) are pentagonal. There are 2 or 3 division 

 -cries beyond the IBr series. The IIBr series are 4(3+4), or some of them may be 2. 

 The IIIBr series are 2 and 4(3+4), sometimes the inner on a post-radial series being 

 2 and the outer 4(3+4), while in other cases they are mostly 4(3+4). All the IVBr 

 series are 4(3+4). The axillaries of the division series are rather large. The ossicles 

 following the axillaries are always partially united laterally. On the articulation 

 between the two first elements of each division series there is a dorsal tubercle, though 

 this may be scarcely noticeable; a similar tubercle occurs on the articulation between 

 the first two brachials, though hero it is less marked. The axillaries of the division 

 series of 4(3+4) form with the segment succeeding sometimes a small lateral boss 

 iivcr the base of the pinnule. The 46-56 arms are about 200 mm. long. They have 

 a narrow dorsal surface and a serrate dorsal profile, and are composed of short uniform 

 brachials. From the very base of the arm the brachials have produced distal ends, 

 this feature becoming less and less marked toward the arm tips so that here the surface 

 of the anus is fairly smooth. The six or seven earliest brachials, especially the first 



