A CAMERATE CRINOID FROM THE UPPER SILURIAN (LUDLOW) MOYDART FORMATIONOF NOVA-SCOTIA, CANADA

Well-preserved fossil echinoderms are uncommon in the Arisaig Group (e arly Silurian to early Devonian) of Nova Scotia. Although not preservi ng sufficient detail to enable specific identification, a crinoid, mon obathrid camerate gen. et sp. indet. from the Moydart Formation (late Silurian, late Ludlow), shows the following features: a long, heteromo rphic (N212) column of circular section and with convex nodals; a broa d, conical dorsal cup with broad, high radials; fixed, uniserial arms which branch twice; 20 long, free arms that are uniserial most proxima lly, but are otherwise biserial; and numerous, elongate, blade-like pi nnules. The column of this species differentiates it from a second tax on commonly preserved perpendicular to bedding in the Moydart Formatio n. Thus, while one species in this formation is preserved autochthonou sly in life position, another forms a crinoid lagerstatte and coquinas of more complete specimens, but is, at best, parautochthonous.