A. Axial cord of arm. | J, Arm-joint. 
a’, Its branches, 7d. Dorsal ligament. 
ae, Ambulacral epithelium. | li, Interarticular ligament. 
B,, Second brachial. | mp, Muscle-plate. 
b, Radial blood-vessel. | m. Ventral or ambulacral nerve. 
br. Plug of calcareous tissue, called a basal rosette by Sars. R,. First radial, 
ce, Coeliac canal, re, Rectum. 
cco, Interradial portion of circular commissure. 7m. Muscles uniting the first and second radials, 
cp. Covering plate, | ste. Subtentacular canal, 
G, Gut. T. Tentacle. 
ge. Genital cord. vrf. Ventral radial furrow. 
ge’. Genital canal. | W, Radial water-vessel, 
ico. Intraradial portion of circular commissure. | x, Plexiform gland, 
Figs. 1-8. Batuycrinus GRraciLis, Wyv. Thoms. 
Fig. 1. Head and upper part of stem, . 
Fig. 2. Middle part of stem, 
Fig. 3. Lowest part of stem, . 2 ; y 7 
Fig. 4. Ventral portion of a transverse section of an arm, 
Fig. 5. An entire section through the middle of an arm-joint, . 
Figs. 6-8. RHIzOCRINUS LOFOTENSIS, Sars. 
Fig. 6. Horizontal section through the lower part of the radials, of 
which there are six, ; : : : P 
Fig. 7. Horizontal section of the calyx of the same individual at the 
level of the articular faces of the radials, . : 
Fig. 8. Horizontal section of the disk of a pentamerous specimen at 
PLATE VIIa. 
The Lettering is the same in all the Figures, 
the level of the second brachials, . A 5 : 
Diam. 
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