CRINOIDEA 



19 



1. Rhizocrinus lofotensis M. Sars. (Fig. 7.) 



Stalk slender, up to ca. 70 mm. long, with up to ca. 65 joints, 

 the longest of which, in the middle of the stalk, are ca. 1 -5 mm. 

 long, 2-3 times as long as broad. The lower part of the 

 stalk usually irregularly bent, lying on 

 the bottom, to which it is anchored by 

 means of the root-like branching appen- 

 dages. Arms short, ca. 10 mm. long, 

 with ca. 5-6 pinnules on each side. Large 

 side-plates along the ambulacral grooves. 

 Calj^x and arms greyish or beautifully 

 yellow in the living specimens. 



Specimens with 4, 6, or 7 arms are 

 commonly met with. 



This sj)ecies aj^pears to be rather 

 uncommon in the British seas, since it 

 has only been recorded from the Faroe 

 Channel (59° 36' N., 7° 20' W., 954 m. ; 

 "Porcupine") and from 53° 58' N., 

 12° 24' W., 687 m. ("Helga"). Else- 

 where it is widely distributed, occurring 

 in the European seas from off Lofoten, 

 on the Norwegian coast, and off south 

 Iceland to the Bay of Biscay. Also on 

 the American side of the Atlantic it is 

 known, occurring from off Florida to 

 Davis Strait. Its bathy metrical dis- 

 tribution is from 140 down to ca. 3000 metres. 



The form occurring off the American coast has been regarded 

 as a separate species, Rhizocrinus Verrilli A. H. Clark ; this has, 

 however, again been withdrawn by its author as being a variety 

 only of Rh. lofotensis. 



Fig. 7. — Rhizocrinus lofo- 

 tensis. About natural 

 size. (After Wyv. 

 Thomson ; from Dan- 

 mark's Fauna.) 



2. Democrinus Perrier. 



Basals distinctly higher than radials, forming a more or less 

 cylindrical calyx, not completely fused, but separated by usually 

 rather distinct sutures. Radials free, not coalesced with the 

 basals. Muscular and non-muscular (ligamentous) articulations 

 regularly alternating throughout the arms. Five simple, un- 

 divided arms. 



One species in British (and European) seas. 



