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ECHINODERMS OF THE BRITISH ISLES 



proximally. Ventral plates pentagonal, with scarcely excavated 

 outer edge. Four, farther out 8, arm spines, the second from below 

 axe-shaped widened at the point (Fig. 122, c). No tentacle scales. 

 Mouth shield rounded triangular. Outer mouth papilla very 

 small, scale-like ; sometimes there are 2 or 3 outer mouth papillae 

 in place of 1. Colour in life reddish-blue or bluish-black on disk, 

 the arms flesh-coloured. Diameter of disk scarcely more than 

 5-6 mm. ; length of arms only six to seven times the diameter 

 of disk. 



Fig. 122. — a-c, Amphiura horealis ; part of oral side (a) and dorsal side (6), 

 three arm-joints, seen from the dorsal side (c). d-/, Amphiura securi- 

 gera ; part of oral side (d) ; part of disk, with radial shields and proximal 

 part of arm (e) ; four arm-joints, seen from the dorsal side (/). All 

 figures x 12. (From Th. Mortensen, Scand. Ech.) 



This species is a proterandric hermaphrodite. It may be 

 found on a dead coral bottom, which fact perhaps indicates 

 that it does not live buried in the ground as do the other 

 Amphiuras. 



From British seas this species has been recorded only from 

 the Faroe Channel (60° 39' N., 3° 9' W., 365 m., " Porcupine "). 

 It is elsewhere known only from the Scandinavian coasts, from 

 Tromso to Skagerrack. Bathymetrical distribution ca. 150-800 m. 



