149 



a~ Centrodorsal truncated conical, the cirri arranged in ten columns, two in each 

 radial area; 60 — 70 cirrus segments 



b 1 brachials after the proximal third of the arm with the central portion of 

 the distal edge produced into long overlapping spines which are more or 

 less fiattened dorsoventrally and rounded or truncated at the tip-, 12 — 16 



arms (Laccadive Islands; 1265 Metres) sentifera 



b 2 brachials with the distal borders not provided with long overlapping spines 

 c 1 70 or more cirrus segments (Malay Archipelago and the Philip- 



pine Islands; 54 — 414 Metres) rustica 



c 3 60 — 63 cirrus segments 



d 1 radials concealed by a narrow rim about the proximal margin of the 

 IBi'j; ends of the basal rays very prominent as high dorsoventrally 

 elongate tubercles which are usually rather lönger than the dorsoventral 

 length of a cirrus socket; sides of the IBrj in the interradial angles 

 cut away to accomodate the ends of the basal rays; 17 — 18 arms 



(Moluccas; 1595 Metres) marginalis 



d 3 no produced proximal border on the IB^ concealing the radials, which 

 form a closed ring about the calyx separating the ends of the basal 

 rays from the IBrj (South Africa; 540 — 810 Metres). . . . magnicirra 



1. Crotalometra flava (Koehler). 



KOEHLER. Revue biol. du nord de la France, vol. 7, 1895, p. 475 {Antedon flava). 



et Vanev. Buil. du Mus. d'hist. nat., Paris, 1910, N° I, p. 31 {Antedon [Crotalometra] flava). 



A. H. Clark. Proc. U.S. National Museum, vol. 40, 191 1, p. 37 {Crotalometra flava). 



2. Crotalometra porrecta (P. H. Carpenter). 



P. H. Carpenter. "Challenger" Reports. Comatulae, 1888, p. 250, pi. 52, figs. 3 — 5 {Antedon 

 porrecta). 



KOEHLER et VANEV. Buil. du Mus. d'hist. nat., Paris, 1910, N" 1, p. 32 {Antedon [Crotalo- 

 metra | porrecta). 



A. H. CLARK. Proc. U.S. National Museum, vol. 40, 191 1, p. n {Crotalometra porrecta). 



Smithsonian Miscellaneous Collections, vol. 61, 1913, N° 15, p. 46 {Crotalometra porrecta). 



3. Crotalometra sentifera A. H. Clark. 



A. H. Clark. Proc. Biol. Soc. Washington, vol. 22, 1909, p. 147 {Crotalometra sentifera). 

 Crinoids of the Indian Ocean, 1912, p. 201, fig. 37, p. 202 {Thalassometra sentifera). 



4. Crotalometra rustica A. H. Clark. 



A. H. Clark. Proc. Biol. Soc. Washington, vol. 22, 1909, p. 80 {Crotalometra rustica). 



Proc. U.S. National Museum, vol. 39, 1911, p. 550 {Crotalometra infelix). 



Crinoids of the Indian Ocean, 1912, p. 198, fig. 36, p. 199 {Thalassometra rustica); 



p. 203 {Thalassometra infelix). 



