POLYCH^TA—BENHAM. 123 



Fig. 118. A dorsal cliaeta viewed in the plane with two flanges (x 45). 



119. A dorsal chseta viewed in the plane at right angles to the above ; it is now 

 curved, and has one broader flange ( X 45). 



120. A portion of a dorsal chseta lying on its two-flanged side, with the third flange 

 projecting iipwards ( X 720). 



121. The tenth abdominal neuropod (x 20), — d., distal process ; p., proximal 

 papifla. 



122. Neuropodial uncinus ( x 360). 



123. The same viewed from above. 



Amyihas membranifera (figs. 124-132). 

 Fig. 124. Anterior end dorsal view (natural size). The missing gills are indicated by 

 the dotted lines. 



125. Anterior end (enlarged) — g., the anterior gill of right side; g. 2, g. 3, the 

 gills, or their bases, of the second and third pairs ; hr., branchiferous segment ; 

 fr., prostomium. 



126. Side view of anterior region ( X 2) — fe.. peristominm ; other letters as above. 



127. Anterior end, seen from in front (X 3), with the tentacular membrane [t.m.) 

 pressed downwards—/., lateral region of the lower lip (peristominm) ; pr., 

 prostomium ; s.o., supra-oral arch. 



128. View from below of the anterior end. dissected from the left side, and the floor 

 pressed down- ;//., ventral gland shields ; I. a., lateral region of the supraoral 

 arch ; /./., inner lower lip or sphincter ; nrp., neurojjods ; pe., peristominm ; 

 t.m., tentacular membrane. 



129. Side view of the abdominal segments. 



130. Thoracic uncinus ( x 360). 



131. Abdominal unchnis ( x 360). 



132. Abdominal uncinus, viewed from above ( X 360). 



