A MONOGRAPH OF THE EXISTING CRINOIDS 231 



P. Cirri with 24-36 (usually 30-33) segments all of which are about twice as long as 



broad at the ends (south of eastern Borneo; 82-88 meters) propinqua (p. 277) 



6 2 . Basal segments of the enlarged proximal pinnules with prominent thin carinate extensions or 



keels on the side toward the arm tip. 



c 1 . IIIBr series always present, all or most of them 4(3 + 4) ; brachials exceedingly short, mostly 

 oblong; cirri with 26-45 (usually 30-35) segments, the longest never so long as broad; 

 median dorsal tubercles or small spines are developed from the twelfth-fourteenth onward; 

 18-27 arms 85-150 mm. long (Andaman Islands to Kwala Cassan and Java; littoral) 



philiberti (p. 313) 

 c 1 . IIIBr series 2, or absent. 



d l . The outer cirrus segments bear long, slender, sharp, and prominent dorsal spines which 



begin abruptly. 

 e l . Cirri stout, with all the component segments broader than long. 



f. Cirri very stout with all the segments much broader than long; 10-13 arms 170-180 



mm. long; cirri XV, 29-30 (Maldive Islands; littoral) flora (p. 333) 



P. Cirri less stout, the longest segments from one-third to one-half again as broad as 

 long; 19-39 (most commonly about 30) arms, 75-85 mm. long; cirri XXI-XXXIII, 



25-34 (usually about 30) (Delagoa Bay) delagoae (p. 334) 



e 2 . Cirri slender or moderately stout, with the longest segments as long as, or longer than, 



broad. 

 f 1 . Larger, the 11-23 arms 100-150 mm. long; brachials in the middle and outer portion 



of the arms more or less wedge-shaped; P 2 and PS composed of 25-33 segments. 



g 1 . Usually 35-40 cirrus segments; P 2 and Pa with 27-33 segments; brachials in the 



middle and outer part of the arms distinctly wedge-shaped, with produced distal 



edges; distal border of radials usually with a row of small bead-like tubercles; 



11-20 arms 100-150 mm. long (Malacca Strait; 0-73 meters).. singnlaris (p. 290) 



<7 2 . Usually 27-30 cirrus segments; P 2 and Pa with 25 segments; brachials in the outer 



half of the arms short and almost oblong, with the distal edges not produced; 



radials concealed; 19-23 arms 120-125 mm. long (Bagamoyo and Zanzibar to 



Waxin and from Kurrachi to Persian Gulf; 0-88 [?89] meters) ..africana (p. 325) 



f 1 . Small, the 12-13 arms 70-85 mm. long; brachials in the middle and outer portions 



of the arms exceedingly short and discoidal; P 2 and P 3 composed of 18-25 segments; 



cirri with 26-35 (usually 30-35) segments, 20-23 mm. long (southern Japan) 



schlegelii (p. 329) 

 d j . The outer cirrus segments bear dorsal tubercles or short, broad, and usually blunt, spines 



which develop very gradually. 



e 1 . Cirri tapering conspicuously distally so that the terminal third or fourth is only about 

 half as broad in lateral view as the proximal portion; cirri almost smooth, with only 

 slight and inconspicuous subterminal dorsal tubercles on the last 10-15 segments; 

 distal cirrus segments always longer than broad, varying from slightly longer than 

 broad to twice as long as broad; cirri long, 30-33 mm. (rather more than one-fourth 

 the arm length); 19 arms 120 mm. long; brachials short; P 3 with 27 segments (off 



western Java; 24 meters) astyanax (p. 284) 



e 2 . Cirri tapering not at all, or only very slightly, distally, the distal segments being never 

 longer than broad and usually markedly broader than long, and bearing well -developed 

 dorsal processes. 

 /'. Cirri with not more than 31 segments. 



g*. Brachials exceedingly short and discoidal, with more or less strongly produced 

 ends; 20-31 cirrus segments; 11-18 arms (Ceylon and Bay of Bengal to Philip- 

 pines; 0-44 [784] meters) bengalensis (p. 321) 



g 1 . Brachials longer, wedge-shaped, the distal ends not produced; 15-18 arms 65-120 

 mm. long (Philippines to Singapore and Amboina; 0-36 meters). .affinis (p. 285) 

 f 2 . Cirri with 30-44 segments. 



g 1 . Cirri with all the segments broader than long. 

 h l . P 3 as large as, or larger than, P a . 



