Plate XV. 



Echinocardium flavescens O. F. M. 



p. 2G, 46. 



Vig. 172. A. young specimen, measuring 1,7 mm., deiuideil of its spines; ventral view. The oesophagus has 



already pierced the buccal membrane. 

 Fig. 173. The same; dorsal view. The periproct, just formed, high up on the bacl;. The fasciolne have begun 



to appear. In the frontal ambulacrum, III, a single pedicel, others being probably lost, 'i'hc 



details of the calycinal system were obscured by some opaque substance contained in the intestine, 



and could not be made out properly. 

 Fig. 174. The peristomal region of a specimen measuring 3 mm. 

 Fig. 175. A part of the peristomal region of a specimen between fig. 173 and 174. 

 Fig. 176. The top of a phyllodean pedicel in the early state, fig. 172. 

 Fig. 177. Another with two rods beginning to form. 

 Fig. 178. The filaments with their rods a little more advanced. 

 Fig. 179. Another with the psellion. 



Fig. 180. Another with the rudiments of three filaments. 

 Fig. 181. The disk of a phyllodean pedicel in a young specimen measuring 5,3 mm., with eight filaments in 



a circle and a ninth filament beginning an inner series. 

 Fig. 182. Spicules from its pseUion. 

 Fig. 183. The peristomal part of an interradiuni from the inside, showing the transverse laminae, p. 26. 



