28 



ECHINODERMS OF THE BRITISH ISLES 



Antedon are found in A. H. Clark's reports on the Crinoids of 

 the Danish '^ Ingolf " Expedition (Vol. IV., 1923, p. 55), and on 

 the Comatulids of the Siboga Expedition (Monogr. XLII. 6, 1918, 

 p. 203).) 



Key to the British species of the genus Antedon. 



Distal edge of brachials thickened and prominent (Fig. IS-i) 



\. A. bifida (Penn.) 

 Distal edge of brachials not thickened and prominent (Fig. IS.o) 



2. A. petasus (Diib. and Kor.) 



F''iG 13. — Part of arm (side view), with genital pinnules, of Antedon 

 bifida (1) and petasus (2) ; a cirrus of A. bifida (3). x 7. 



1. Antedon bifida (Pennant). (Fig. 14.) 



(Syn. Antedon rosaceus (Linck) ; ? Antedon Milleri 

 Wyv. Thomson.) 



Cirri usually ca. xxv, with rarely more than 15 segments, 

 increasing in width very gradually (Fig. I33). Pinnule^ with 

 ca. 35 segments. Distal edge of brachials thickened and prom- 

 inent (Fig. 13i). Proximal 6-7 joints of genital pinnules with 

 rather prominent spines at the distal outer corner ; beyond 

 these the pinnule joints diminish rapidly in size (Fig. 13^); 

 genital organ confined to basal half of pinnule. Colour in life 

 very variable — rosy to deep purple, yellow or orange, or mottled 

 and spotted. 



