AMERICAN SILURIAN CRINOIDS 
227 
PAGE 
Myelodactylus brachiatus Hall 87 
Fig. 19. Complete stem with crown preserved, with long, slender proximal neck following the 
reverse curve outside of principal coil; has branching cirri, limited to distal end. 
X3/2. 
Rochester shale; Lockport, New York. 
Myelodactylus keyserensis Springer 87 
Fig. 20. Nearly complete specimen, with crown fully exposed by removal of cirri ; seen from 
anterior radius, with unbranched posterior radius to the left; cirri paired on succes- 
sive columnals. 
20a. Calyx and lower part of arms, from left anterior radius. X 2. 
Helderbergian, Keyser formation; Keyser, West Virginia. 
Myelodactylus schucherti Springer 87 
Fig. 21. The type, with both distal and proximal portions broken off, leaving one coil of the 
crescentic region, followed by the reverse curve and very robust proximal neck 
which has alternate lenticular ossicles; cirri in crescentic region paired on successive 
columnals. 
Helderbergian, Linden formation; Benton County, Tennessee. 
Myelodactylus nodosarius (Hall) 87 
Fig. 22. One of Hall’s types, showing great size of the ponderous cirri compared with smaller 
stem, and bulbous terminal at distal end. Coll. New York State Museum, Albany. 
23. Distal end of stem, showing bulb, cirri, and relative size of small first cirrals. Same 
collection. 
24. Inner side of same structures in another specimen. Coll. Yale University Museum. 
Helderbergian, New Scotland formation; Schoharie County, New York. 
All the figures on this plate are taken from the author’s work on “ Unusual Forms 
of Crinoids,” Proc. U. S. National Museum, vol. 67, 1026, plates r to 6. 
