132 



CONNECTICUT GEOL. AND NAT. HIST. SURVEY. 



[Bull. 



the body are closely crowded calcareous deposits of characteristic 

 form (Fig. 23). They greatly increase the firmness of the 

 integument. Some of these deposits are quite symmetrical, while 

 others are very irregular. The most typical shape is that of a 

 table in form of a parallelogram, perforated by four oval holes, 

 and surmounted by a spire consisting of two rods with a few 

 sharp points at the apex (Fig. 23). Others are rectangular, with 

 six holes, and a small spire. Still others have eight, ten, or 

 occasionally more holes. Some are considerably elongated, and, 

 when unusually slender, have one or two small holes in each 

 extremity. The vast majority have graceful, curved or wavy 

 outlines, and are remarkably symmetrical. At the posterior end 

 of the body the tables become densely packed together, and are 

 of much larger size than those found elsewhere. Near the 

 cloaca the spire of the tables becomes much reduced, the deposits 

 assuming the form of large perforated plates. 



The cloacal opening is supported by a ring of crowded cal- 

 careous plates of large size, but quite irregular in shape 

 (Fig. 24). 



In the pedicels the calcareous deposits are slender tables, and 

 near the extremity are reduced to supporting rods with perforated 

 ends. The tip of each pedicel has a terminal perforated plate 

 (Fig. 24). 



Fig. 24. Cucumaria pulcherrima. Outlines of calcareous plates. A, 

 from cloaca; B, terminal disks of pedicels. (X 150.) 



In the tentacles there are a few small plates of very irregular 

 outline, with an occasional one of much larger size. 



