PLATE XXXIII. 
Figs. 1, la . — Thuiaria pectinata (p. 69). 
Fig. 1. — A colony ; natural size. 
Fig. la. — Part of a colony ; magnified 15 diameters. 
Figs. 2, 2a . — Thuiaria hyalina (p. 69). 
Fig. 2. — Part of a colony ; natural size. 
Fig. 2a. — Part of a colony ; magnified 15 diameters. It shows the permanently exserted 
condition of the hydranths, and the ectodermal bands by which the body of 
the hydranth is connected to the walls of the hydrotheca. 
