CRINOID GENUS SCYPHOCRINUS 65 



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Scyphocrinus elegans Zenker — Continued 30 



Fig. 12. Cross-section, natural size, of brachials at different heights, to show the 

 taper of arm ; a, IIIBr next above bifurcation, width 6.5 mm. ; b, VBr 

 an inch below bifurcation, and 10 cm. above a, width 2.75 mm. ; c, VIBr 

 15 cm. above b, width 2 mm. All from the same ray. d, a higher 

 VIBr from a similar specimen, width 1.15 mm., which at the same rate 

 of diminution would be about 22 cm. above the last. This would give 

 a length of about 48 cm. (18 inches) from lower IIIBr to a higher 

 VIBr of about 1 mm. width. As the distal part of the arm would 

 probably diminish to 5 mm., this would add at least 10 cm., making the 

 total probable length of arm in life about 55 to 60 cm., or at least 

 22 inches. 



