226 



Echinoderras, in order I 

 growth. 



The stomach and intestinal canal either pass straight or in a 

 spiral course through the body, as in the sea urchins (Fig 103) and 

 Holothurians (Fig. 83), and open out at the opposite end ; or, as 

 in the Antedon (Comatula), the anal opening is situated near the 

 mouth, while in the Ophiurans (Fig. 85) and Luidia and Astro- 

 pecten, low starfishes, the undigested food is rejected from the 

 mouth. In the starfishes and Holothurians, the alimentary canal 

 opens into five voluminous csecal appendages. These are wanting 

 in the Ophiurans, and there are but two in Astropecten. They 

 are in connection with the complicated 



//v branches out into the ra * s of the star * 



W W bulacra. The water fills the tubes 



ual. The ovaries and testes 

 gland-like masses situated at 



of the arms in the starfishes, 

 i the sea urchins. The ovaries are red or yellow, the male glands 



