354 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



the cirrus segments, and especially the lower ones, are broader than long. The middle 

 and outer segments have a more or less distinct dorsal spine. 



The radials are almost entirely, or quite, concealed. The IBri are rather sharply 

 convex and rise to a median tubercle at their junction with the wide IBr 2 (axillaries). 

 There is a similar but smaller tubercle on the articulation between the first two 

 brachials. In large specimens the elements of the IBr series and the first two brachials 

 are sometimes slightly wallsided, with straight edges and the margins of the dorsal 

 surface flattened. 



The 10 arms are 125 to 150 mm. long and are composed of nearly 300 brachials. 

 The third and next following brachials are smooth, rounded, and nearly oblong, with 

 a tendency to alternating tubercular elevations at their junctions. After the second 

 syzygy the brachials are shortly triangular and slightly overlapping, gradually becom- 

 ing nearly oblong, but remaining always much broader than long. 



Syzygies occur between brachials 3+4 and 9+10 or 10+11, and often also 

 between brachials 14+15 or 15 + 16. The distal intersyzygial interval is 4 to 20 

 muscular articulations, usually 9 or 11, the intervals being somewhat longer in the 

 outer part of the arms than in their first third. 



P! and P a are about 8 mm. long and consist of some 18 moderately stout segments 

 of which some of the middle ones are longer than broad. The pinnules of the next 

 five or six brachials (fifth to tenth) are somewhat longer and stiffer, with much stouter 

 segments, sometimes the second and sometimes the third pair being the largest. The 

 pinnules of the fourth pair are occasionally much smaller than those of the third, 

 and those of the fifth pair are always much so, after which the length of the segments 

 increases and the later pinnules become long and slender. 



The disk is naked and is 10 or 12 mm. in diameter. Sacculi are abundant. 



The color in alcohol is dark reddish brown, bleaching to white. 



The figures of Antedon milberti given in the Challenger report represent this 

 species. Carpenter said that in some individuals of what he called Antedon milberti 

 (=molleri+tessellata j rdiscoidea') the axillaries and lower brachials have indications 

 of straight lateral edges and of the peculiar wall-sided character that he described 

 as distinctive of the Basicurva group, and that this is most marked in the specimen 

 from Challenger station 203, which differs from all the other examples of the type that 

 he had seen in showing a considerable portion of the radials externally. Their length 

 is more than half that of the IBr 1( and the tubercles that the latter form with the 

 pentagonal axillaries are less prominent than usual. Both ossicles, and also the first 

 two brachials, have the margins of the dorsal surface flattened, with straight lateral 

 edges, and on some arms this character also extends to the hypozygal of the first 

 syzygial pair (third brachial). But Carpenter remarked that this wallsidedness is 

 always much less distinct than it is in the Basicurva group, and in some examples it 

 is scarcely visible at all, while there are no indications of flattening of the sides of Pj. 



The specimen from Calbayog, Samar, has the arms 145 mm. long and the cirri 

 XIII, 40, 30 mm. long. The cirrus segments are subequal, all being about twice as 

 broad as long. The dorsal spines begin on the twelfth segment. 



A cirrus on the specimen from Port Galera, Mindoro, has 38 segments. Dorsal 

 spines begin on the ninth segment. 



