PLATE II. 
Halysites peristephesicus, Eth. Jil. 
Corallum seen from above, exhibiting the long, clustered, and labyrinthine fenestrules 
and corallite chains, more or less revolving around given centres. 
Portion of a corallum, longitudinal aspect, exhibiting the long corallites, and uneven 
base of the former. 
Another corallum, seen from above, exhibiting the apparent revolution of the corallite 
chains in a more marked manner than in Fig. 1. 
