S6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 6l 



corners ; P 3 is about like F 1 ; P 4 is shorter, and P- is shorter still ; 

 sometimes P x is considerably shorter than P 2 or than P 3 . 



DECAMETRA MOEBIUSI A. H. Clark 



Antedon leevissima 1902. Bell, in Gardiner, Fauna and Geography of the 



Maldive and Laccadive Archipelagoes, vol. 1, part 3, p. 224 (1). 

 Decametra mobiusi 191 1. A. H. Clark, Proc. U. S. Nat. Mus., vol. 40, p. 31. 



1. Fadiffolu, Maldives.— One specimen with arms 30 mm. long; 

 there are 15 cirrus segments; P 2 is slender, not greatly longer than 

 P x , composed of elongated segments with overlapping distal ends ; 

 P x is longer than P 3 and the following pinnules. 



2. Mulilos, Maldives.- — Three specimens with an arm length of 

 from 55 mm. to 60 mm. ; the cirri are XIV, 15, rather slender; P x is 

 about two-thirds as long as P 2 , much more slender and less stiffened ; 

 P, is long but comparatively slender, with twelve segments, of which 

 the distal are twice as long as broad and have projecting distal edges ; 

 P 3 and the following pinnules are shorter than P x . 



DECAMETRA TAPROBANES (A. H. Clark) 



Antedon laevissima 1902. Bell, in Gardiner, Fauna and Geography of 

 the Maldive and Laccadive Archipelagoes, vol. 1, part 3, p. 224 (1, 2, 3). 



i. Fadiffolu, Mulilos, Maldives.-— One specimen. 



2. Mulilos, Maldives. — Two specimens ; the cirri are XIV, 24 ; 

 P x is soft ; P 3 resembles P 2 , but is smaller. 



3. Muhlos, Maldives. — One specimen ; there are 23 cirrus seg- 

 ments ; P 2 is much enlarged, but F x and P 3 are also enlarged some- 

 what. 



DECAMETRA ARABICA A. H. Clark 



Antedon carinata Brit. Mus., MS. (1). 



Description. — The cirri are XIX, 26-27, 13 mm. long, slender; the 

 proximal segments about twice as broad as long, the terminal about 

 as long as broad ; the ninth or tenth and following bear small paired 

 dorsal spines. 



The ten arms, which resemble those of the other species of the 

 genus, are no mm. long. 



P a is absent ; P x is very small and weak, 4.5 mm. long; P 2 is 9 mm. 

 long, composed of fifteen segments, most of which are twice as long 

 as broad, with the distal edges produced and spinous and the distal 

 angles produced, suggesting the conditions seen in Oligometra scr- 

 ripinna; the pinnule is comparatively slender, though stiff, and 

 tapers evenly to the tip ; P 3 is similar but shorter, 6 mm. to 7 mm. 



