22 ECHINODERMS OF THE BRITISH ISLES 



S.W. of Iceland (61° 44' N., 30° 29' W., 2075 m., '' Ingolf ") ; 

 31. recuperatus (Perrier) (Syn. Bathycrinus, Ilycrinus recuperatus 

 Perr.), between Azores and S])ain ("Talisman"), and 35° 36' N., 

 8° 23' W. (•• Michael Sars ""), 2300-4255 m. ; M. Perrieri (Koehler 

 and Vaney) (Syn. Bathycrinus Perrieri Koehler and Vaney), 

 30° 3' N., 14° 2' W., 2212 m. (" Talisman "). These three species 

 are thus distinguished : 



1. 6 radials. 12 arms . . M. sexradiatus A. H. Clark 

 5 „ 10 „ 2 



2. Basals fused into a solid ring, showing no sutures 



M. Perrieri (Koehler and Vaney) 

 Basals not fused together, sutures between them distinct 



M. recuperatus (Perrier) 



II. Family Atelecrinid^ 



Free, unstalked Crinoids, with a long, conical centro-dorsal, 

 with cirrus-sockets arranged in (usually) ten equidistant columns, 

 each socket bordered above and on the sides by a horseshoe- 

 shaped raised rim. Arms 5 or 10 in number. 



Only one genus known in the British seas (and the whole 

 Atlantic). 



1. Atelecrinus P. H. Carpenter. 



Arms dividing on second post-radial joint, 10 in number. No 

 pinnules on the lower 10-12 arm -joints. Basals more or less 

 distinctly visible above the upper edge of the centro-dorsal. 



The species of this genus are exceedingly brittle, and nearly 

 always come up entirely broken, with only the basal part of the 

 arms preserved and most of the cirri lost. All are deej^-sea forms. 



Only one species in British seas. 



I. Atelecrinus helgce A. H. Clark. (Fig. 10.) 



Cirrus - sockets arranged in two fairl}^ regular, very closely 

 crowded columns in each radius, 3-4 to each column. Basals very 

 short, distinct only between the radials ; the part below the 

 radials is hidden or reduced to a mere line separating the latter 

 from the centro-dorsal ; radials short, 4-5 times as broad as long 

 in the median line. 



