134 



CONNECTICUT GEOL. AND NAT. HIST. SURVEY. 



[Bull. 



perforated calcareous plates, and somewhat similar plates occur 

 more sparingly in the smaller branches. They are either rod-like 

 or broad, and are commonly perforated by six or more holes 

 (Fig. 25). 



The body walls, especially in mature specimens, are without 

 calcareous deposits in the greater part of the body. At both 

 extremities, however, there are numerous peculiar calcareous 

 deposits known as " tables." These tables are more or less 

 nearly square or rectangular, and are perforated by about eight 

 rounded holes. At right angles to this plate is the so-called spire, 

 made up of about four short rods ending in teeth and connected 

 by one or two cross processes (Fig. 25). 



Fig. 25. Outlines of calcareous plates of Thyone briareus. A, 

 terminal plate of pedicel; B, supporting plates of pedicels; C, 

 plates from tentacles; D, plates (tables) from body-walls. 



The slender pedicels, or tube-feet, are very numerous, and 

 are scattered irregularly all over the body. Occasionally they 

 appear to be arranged in five very broad longitudinal bands, 

 although such bands are not distinctly separated from each other. 

 The pedicels of the ventral surface are broader than those of the 

 dorsal side of the body, the latter commonly tapering to a point. 

 In the extremity of the pedicel is a terminal circular plate (Fig. 

 25), perforated by many minute holes. In the walls of the ped- 

 icels are other perforated plates, some of which are modified to 

 form supporting plates, while others are provided with a short 

 spire (Fig. 25). 



The cloacal opening has five groups of small papillae, and a 

 calcareous ring with the five tooth-like processes known as the 

 anal teeth. 



