A MONOGRAPH OF THE EXISTING CRINOIDS 331 



then gradually oblong again and decreasing in length so that the brachials in the distal 

 half of the arm are extremely short and discoidal, with projecting distal borders. 



Syzygies occur between brachials 3 + 4 (in one case between brachials 4 + 5), again 

 from between brachials 11 + 12 to between brachials 17 + 18, with occasionally an 

 additional syzygy between brachials 9 + 10, and distally at intervals of 11-25 muscular 

 articulations. 



Pi is about 5 mm. long, comparatively slender and tapering evenly from the base 

 to the delicate tip, with about 18 segments, all of which are about as long as broad. 

 P 2 is about 7.5 mm. in length, slightly stouter than Pj but becoming slender and delicate 

 distally, with about 18 segments of which the first two are not quite so long as broad, 

 the next two are about as long as broad, and the following gradually become elongated 

 and about twice as long as broad distally. P 3 is about 8 mm. long, stouter and stiffer 

 than P 2 , though the component segments are in the same number and of the same 

 proportions. P 4 resembles P 3 but is shorter and somewhat less stout with about 12 

 segments of which the first two or three are not quite so long as broad and those 

 following are about as long as broad, becoming rather longer than broad distally. 

 Distally the pinnules slowly increase in length and become more slender. The distal 

 pinnules are 6 mm. long, moderately slender, with about 20 segments of which the 

 first is not so long as broad, the second is about as long as broad, and those following 

 become gradually longer, reaching a length of about twice the breadth distally. 



The color in alcohol is dull flesh color, with the perisome brown. 



Notes. — A specimen without locahty in the Hamburg Museum may be described 

 as follows: The cirri are XV, 29-35, from 20 to 23 mm. long. The longer proximal 

 segments are about as long as, or slightly longer than, broad. The distal segments 

 are nearly twice as broad as their median length. The twelfth, thirteenth, or four- 

 teenth and following segments bear a long and prominent, rather broad, dorsal spine. 

 The segments that bear the dorsal spines have the dorsal surface flattened so that 

 there is a rather conspicuous rounded ridge along the boundary between the lateral 

 and dorsal surfaces. The radials have a finely beaded distal edge as is frequently the 

 case in H. philiberti. The 12 arms are 85 mm. long. One postradial series bears a 

 single IIBr 4(3+4) series, which carries internally a IIBr 2 series. 



P, is small and slender, 6 mm. long, with 24 segments, which become about as 

 long as broad on the fifth, the remainder being slightly longer than broad. The 

 second-eighth bear a high broad finely spinous carinate process, which rapidly de- 

 creases in height after the third. P 2 is 10 mm. long, with 25 segments, of which the 

 fifth-seventh are about as long as broad and the distal are twice as long as broad. 

 The second-ninth are diminishingly carinate, the outer border of the carination being 

 convex on the second but parallel to the longitudinal axis of the segment on the 

 remainder. The pinnule is evenly tapering, and is proportionately larger than P ( . 

 P 3 is 13 mm. long, with 24 segments. It resembles P 2 , but the supplementary ridge 

 is strongly indicated, and it becomes more distinctly prismatic distally. P 4 is 7 mm, 

 long, with 18 segments, the second-fifth with carinate processes which are propor- 

 tionately higher than those on the corresponding segments of the preceding pinnules. 

 P s is 4.5 mm. long, with 14 segments, of which the second-fifth are very strongly and 

 the sixth is somewhat carinate. The following pinnules resemble P 6 . The distal 



