A MONOGRAPH OF THE EXISTING CRINOIDS 563 



broader than long with small dorsal tubercles or short spines which begin on the 

 twelfth segment. 



The 47 arms are 130 mm. long. The arms are developed in 2,2,2,2 order, or in 

 2,1,1,2-2,1,1,2 order on each postradial series. 



P 2 is 16 mm. long and is composed of 28 segments. P 3 is 18 mm. long, with 27 

 segments, most of which are twice as long as broad, becoming much elongated distally. 



The preceding description is based on the type specimen of Dichrometra dofleini. 



Notes. — The specimen from eastern Asia has 45 arms 100 mm. long. The cirri 

 are 27 mm. long and are composed of 32-33 segments, of which the outer bear small 

 dorsal tubercles. The division series are bordered by broad lateral extensions whereby 

 they are almost in lateral apposition. Pj is 10 mm. long, with 24 segments. P 2 is 

 17 mm. long, with 29 segments. P 3 is 20 mm. long, with 29 segments. P 4 is 13 mm. 

 long, with 21 segments. 



Professor de LorioPs description of the type specimen of Antedon doderleini is as 

 follows: The centrodorsal is rather thick and is pentagonal in outline. The bare 

 dorsal pole is only 2 mm. in diameter and is covered with small granules. The cirri 

 are irregularly arranged. The cirri are XXXIV, 32-35, from 20 to 25 mm. long and 

 0.5 to 0.75 mm. in diameter. The segments are cylindrical, not compressed laterally, 

 smooth, longer than broad, and joined exactly end to end without any dorsal projec- 

 tions. The terminal segments are slightly wedge-shaped, the ventral profile being 

 longer than the dorsal. The opposing spine is very small. The terminal claw is a 

 pointed hook. The radials are very short and scarcely visible. The IB^ are rectangu- 

 lar, much broader than long, with the dorsal surface convex, and are in lateral contact 

 with those on either side. The IBr 2 (axillaries) are relatively short, much broader 

 than long, with their lateral borders free and slightly flattened. The elements of the 

 IBr series are entirely smooth dorsally and are united by synarthry. The IIBr and 

 IIIBr series are 2, with the elements united by synarthry. 



There are 20 long, very slender, very flexible, elegant, and entirely smooth arms 

 which are provided with rather long delicate pinnules. The arms are 150 mm. in 

 length. The number of arms is not the same on the several postradial series. One 

 postradial series bears two IIBr 2 series and a IIIBr series on each of the two IIBr 

 series, giving six arms. The next has only a single IIBr series, which carries a single 

 IIIBr series, giving four arms. The third postradial series bears two IIBr series and 

 no IIIBr series, giving four arms. The fourth has a single IIBr series and no IIIBr 

 series, giving three arms. The fifth bears one IIBr series and one IIIBr series, giving 

 three arms only; but one of the articular faces of the IBr axillary bears a normal 

 ossicle on which is a small axillary ossicle that is not one-third the width of the first 

 and carries two abortive arms 8 mm. long, of which one has an axillary ossicle, giving 

 rise to two still shorter arms. These arms bear very small pinnules. The brachials 

 are strongly convex dorsally, entirely smooth, alternately, regularly, and uniformly 

 tapered toward one side. The two first brachials are slightly flattened laterally. The 

 first syzygy is between brachials 3+4 (or also between brachials 4 + 5), and the second 

 is from 8 to 13 muscular articulations beyond. The distal intersyzygial interval is 

 6, 8, 9, or 10 muscular articulations. Sometimes there are two syzygial pairs in 

 succession. 



