A MONOGRAPH OF THE EXISTING CRINOIDS 257 



than broad and those following are tolerably equal. The eleventh segment and its 

 successors bear strong forward projecting dorsal spines which diminish again after 

 about the twenty-fifth segment. The radials are partially visible, and have crenulated 

 distal edges. The IB^ are trapezoidal, closely united laterally, and rising rather 

 sharply toward the middle of their junction with the pentagonal axillaries, which 

 are about twice their length. The postradial series are very close together, and divide 

 twice, or sometimes three times. The IIBr series are 4(3 + 4) and the IIIBr series 

 are 2. The first 2 segments beyond each axillary form a slight tubercidar elevation 

 (synarthrial tubercle) at the middle line of their junction. The first brachials are 

 rhomboidal and are closely united laterally. The second brachials are longer and 

 are sharply wedge-shaped. The first syzygial pair (composed of brachials 3 + 4) and 

 the five or six following brachials are short and oblong, and those succeeding are 

 triangular, more than twice as broad as long, and overlapping, gradually becoming 

 smoother and more oblong in the middle and outer parts of the arms. Syzygies occur 

 between brachials 3 + 4, again from between brachials 13+14 to between brachials 

 14 + 15, and distally at intervals of 8-11 muscular articulations. 



The pinnules are variable. P D seems to have been less stout than Pj P a is 

 small, usually less than half the length of P b . On the outer arms of the postradial 

 series the fifth, sixth, and seventh brachials bear large pinnules (P 2 , P b , and P 3 ) like 

 that on the second (P x ). Sometimes P 3 and sometimes P 3 is the largest. The pinnules 

 of the next pair, on the eighth and ninth segments (P 4 and P d ), are smaller again. 

 On the inner arms the fifth brachial bears a small pinnule (P 2 ) like that on the fourth 

 (P a ), and the next two pairs are large, the second pair, on the eighth and ninth bra- 

 chials (P c and P 4 ) being the larger. Sometimes, however, the only two really large 

 pinnules are those of the seventh and eighth brachials (P 3 and P ), the preceding pair 

 being smaller, but not especially so, like P a . These long lower pinnules consist of 

 about 25 stout segments the distal ends of which have forward -projecting lateral 

 processes. In the large lower segments these are chiefly limited to the outer side, 

 but they appear on both sides in the later segments. Similar but less marked processes 

 are visible on the cylindrical segments of the remaining pinnules, which increase again 

 in size after the fifth pair but never become so long as the large lower pinnules. 

 The color of the skeleton seems to have been white and that of the perisome purplish. 



Carpenter said that the preceding description was based upon some dried frag- 

 ments of a moderately large Antedon, which appeared to be new. He said that it is 

 altogether a larger species than variipinna, from which it is readily distinguished by its 

 crenulated radials, tubercular arm bases, and smoother arms, while the inequality 

 in the sizes of the lower pinnules is not of the same character in the two species. 



In the specimen from Tonkin the cirri have 44-48 segments, the outer with 

 dorsal knobs. The IIBr series are 4 (3+4). Of the eight IIIBr series, four are 2 

 and four are 4 (3+4). The single IVBr series is 3. One of the IBr series is 6 (5+6), 

 with a pinnule on the fourth element. There are 27+ arms. P 3 is the longest pinnule, 

 30 mm. long with 33 segments. The distal segments have the distal portion everted 

 and spinous, and a little angular. There are faint tubercles at the distal outer borders. 



The Annam specimen has 32-36 cirrus segments, each with a dorsal longitudinal 

 keel tending to form an indistinct dorsal tubercle. The IIBr series are 4 (3+4). 

 Of the three IIIBr series, two are 2 and one is 4 (3+4). The radials are visible; 



