284 



PART II. SYSTEMATIC ACCOUNT 



irregular rows (Fig. BB133C). The platelets are much narrower at the front 

 end, and their anterior section, bearing the anterior group of teeth, is only a 

 quarter the length and half the breadth of the hind section (Fig. BB133D). 

 The toothed platelets are 14—16/x long. 



°l 0.2 



— da 



— dp 



Fig. BB133. Siboglinum subligatum: A - part of the nonmetameric region of the trunk, from the 

 ventral side and a little to the left; В - region of the girdles from the left; С - part of a girdle; 

 D - toothed platelet. 



an - girdles ; da - anterior group of teeth ; dp - posterior group of teeth ; g - glandular portion of 

 integument; pa 2 - papillae in front of the girdles; if -dorsal glandular shield; v- ventral papilla 

 behind the girdles ; vv - ventral blood vessel seen by transparency. 



The postannular region begins without the usual stalk-like waist. Single 

 large conical plaqueless ventral papillae are spaced along its whole length at 

 more or less equal and rather large intervals (Fig. CC1332?). The epidermis 

 near each papilla is distinguished by the rich whiteness (in reflected light) 

 of its granular gland cells like those of the preannular region of the trunk. 



