II. Dibviston, 
CRINOIDEA SEMIARTICULATA. 
Character of the Division. 
Tue plate-like joints resting on the superior columnar joint, and forming 
the cup containing the viscera, articulate by transverse processes, having a mi- 
nute central perforation. 
Observation. 
Although I am acquainted with but one species strictly possessing the cha- 
racter assigned to it (viz. that which serves me as the type for the genus 
» © Poteriocrinites) yet I thought it advisable to constitute the division Semiar- 
TICULATA, to mark in a more conspicuous manner the transition from regularly 
articulating joints to plates adhering only by muscular sutures. 
