CTENOPHOEA 



881 



( >r purple. These spicules are best seen by black-ground illumination, 

 especially when viewed by the binocular microscope. They are, of 



course, to be sepa- 

 rated from the 

 animal substance in 

 the same manner as 

 the calcareous spi- 

 cules of sponges ; 

 and they should be 

 mounted, like them, 

 in Canada balsam. 

 The spicules al\\:iy- 

 possess an oi-guiiu 

 basis, as is proved 

 by the fact that 

 when their lime is 

 dissolved by dilute 

 acid a gelatinous- 

 lopking residuum is 

 left which preserves 

 the form of the 

 spicule. 



The Ctenopkora, 

 or ' comb-bearers,' 

 are so named from 

 the comb-like ar- 

 rangement of the 

 rows] J of tiny 



FIG. 669. 1. Etij>/;i/:-iiiiii>< stationis, with its tentacles 

 extended, about twice the natural size: -in, mouth; c, 

 ctenophoral plate ; t, tentacular apparatus. (After Chun.) 

 2. Diagrammatic view of Hurmipltora plumosa, seen 

 from the aboral pole : c, as before ; tv, tentacular vessel ; 

 PPt polar plates. (After Chun.) 



FIG. 070. - Bi mi- 

 Forskalii, show- 

 ing the tubular 

 prolongations of 

 the stomach. 



' paddles ' by the movement of which the bodies of these animals are 

 propelled. A very beautiful and not uncommon representative of 



> L 



