no. 1808. RECENT AFRICAN CRINOIDS— CLARK. 29 



united for about the proximal two-thirds; third and fourth brachials 

 (syzygial pair) slightly longer than broad to slightly broader than 

 long; following three to five or six brachials oblong, about twice as 

 broad as long, then becoming very obliquely wedge-shaped, almost 

 triangular, half again as broad as long, and in the distal part of the 

 arm nearly or quite as broad as long; there is a slight development 

 of small spines along the distal edges of the brachials. Syzygies 

 occur between the third and fourth brachials, again between the 

 twenty-first and twenty-second to thirtieth and thirty-first, and dis- 

 tally at intervals of from nine to twenty-five (usually about fourteen) 

 oblique muscular articulations. 



P x small, slender, and weak, 5 mm. or 6 mm. long, with 18 or 20 

 segments, of which the second, third, and fourth bear broad carinate 

 processes; first four segments broader than long, the fifth about as 

 long as broad, the following slightly longer than broad, becoming 

 about half again as long as broad distally; P 2 stout and stiff, 9 mm. 

 long, with fifteen to eighteen segments, and much the largest pinnule 

 on the arm, though not nearly so stout as in most of the allied species; 

 the first two or three segments are broader than long, the following 

 about as long as broad, distally slightly longer than broad; the distal 

 ends of the segments are slightly produced and finely spinous, espec- 

 ially in the outer part; following pinnules small and weak, 4 mm. 

 long, with eleven segments, the first two broader than long, the third 

 about as long as broad, the following slowly increasing in length, 

 becoming half again as long as broad distally ; distal pinnules very 

 slender, 9 mm. long, with twenty segments, which become twice as 

 long as broad or somewhat longer distally. 



The color is purple, the cirri and P 2 yellow, the remaining pinnules 

 white. 



Localities. — Mauritius ; Seychelles. 



Depth. — Littoral, and down to 39 fathoms. 



Remarks. — This redescription is based upon a fine specimen in the 

 Berlin Museum. The whole animal is very slender, which, with the 

 strong carination of the lower pinnules, makes this species an easy 

 one to recognize. 



A fine series of eight specimens, four from Mauritius (the types) 

 and four from the Seychelles (Sea Lark expedition) show that the 

 arms vary from twelve to twenty-two in number, though the former 

 is only found in young examples; the usual number appears to be 

 between fifteen and twenty. The arm division is always external as 

 in the other species of Cenometra. The arms are from 90 mm. to 100 

 mm. long. The cirri are XIV-XX, 32-41 (usually about 35) ; P 2 is, 

 for the genus, comparatively slender, and possesses from nineteen to 

 twenty-one segments. The strong carination of the earlier segments 

 of the proximal pinnules make this species an easy one to recognize. 



