482 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



brachial syzygial; arm-joints iii \ i, squarish, the succeeding triangular, and the more distal gradually 

 overlapping. 



Colour purplish, with the free ends of the arms white. 



The single specimen is a good deal broken, but it is interesting as belonging to a series of the 

 [Spinifera] group of which Dr. Carpenter knew only one type. 



In the type specimen, which I examined in London in 1910, the cirri are XVIII, 

 21-25 17 mm. long. The longest proximal cirrus segments are about one-third 

 again as long as broad; the 13 outermost segments arc slightly broader than long and 

 bear moderately developed dorsal spines. The 32 arms are 60 mm. long. The IIBr 

 and IIIBr series are 2 and are in close lateral apposition. The lateral borders of the 

 elements of the division series appear to be somewhat produced. P 2 is the longest 

 and largest pinnule and is about half again as long as P,. It is enlarged, long, and 

 slightly stiffened, and tapers evenly to a delicate and flagellate tip exactly as in 

 L. palmata. It is composed of 16-21 segments, which become about as long as broad 

 on the third and twice as long as broad distally. It is considerably larger on the 

 outer arms arising from each IBr axillary than on the inner. P, is similar to P 2 

 but only two-thirds as long and not so stout, and it tapers somewhat more rapidly. 

 P, is about as long as P, but is slightly stouter and tapers less rapidly, thus more nearly 

 resembling P 2 ; it is composed of 16 segments. The following pinnules are small and 

 weak. This is an immature specimen of the form called similis (see page 485) by 

 Carpenter. 



In the young specimen from Annam, according to Gisl6n, the cirri are 14-15 mm. 

 long, with 19-23 segments. There are 28 arms. P 2 is by far the largest pinnule. 



In the specimen from Cochinchina, which is larger and has broader arm bases, 

 the diameter of the centrodorsal is 5 mm. The cirri are all broken. There are 40 arms, 

 with one IVBr series present. P 2 is much longer than Pi or P 3 . 



The two specimens in the Challenger collection from the Cebu reefs were described 

 by Carpenter as a new species under the name of Antedon conjungens. According to 

 him the centrodorsal is a thick slightly convex disk bearing marginal cirri. The cirri 

 are about XXVIII, 20-30. The segments are uniform, the later ones somewhat com- 

 pressed laterally with a sharp dorsal keel that passes into the opposing spine. The 

 radials are concealed. The IBr, are broadly hexagonal and are partly united laterally. 

 The IBr 2 (axillaries) are pentagonal. The postradial series, which are laterally free 

 from the IBr, onward, divide three and occasionally four times. All the division 

 series are 2. The outer sides of the elements of the IIBr and IIIBr series are much 

 produced toward the ventral surface so that each of the five divisions of the disk, as 

 seen from the ventral side, has more or less distinct bony margins. The arms are 

 rather over 40 in number, 100 mm. long, and composed of about 150 brachials of 

 which the first few are discoidal and their successors shortly triangular, gradually 

 becoming oblong but always much broader than long. Syzygies occur between 

 brachials 3+4, again from between brachials 15+16 to between brachials 21+22 

 (generally at about the fifteenth or sixteenth brachials), and distally at intervals of 

 from 6 to 12 (usually 8 or 9) muscular articulations. Of the four or more arms borne 

 on each IIBr axillary the two outermost have much larger lower pinnules than the 

 inner. P 2 may reach 15 mm. in length and be composed of nearly 30 segments, of 



