304 



PART II. SYSTEMATIC ACCOUNT 



cells. In one individual there is a slight colourless thickening of the cuticle 

 on the tip of each postannular papilla. 



The tentacle reaches 12 mm long and it may possibly be capable of much 

 greater elongation. The fore-part of the body is 0-74 to 1-2 mm long. The 



an' 



Юу 



0.2 



мм 



Fig. NN133. Siboglinum ceylonicum: A - region of the girdles from the ventral side; В - platelets 



of the first girdle; С - platelets of the hind girdle; D - toothed platelet from the side. 



an - girdles; da - anterior group of teeth; dp - posterior group of teeth; v - ventral papilla. 



