POLYCH.^TA. — BENHAM. 149 



minute, for when rolling the worm over till the following 

 segments are in profile so as to show the bristles, I can see 

 none on the second segment. Possibly they are embedded 

 in the glandular tissue, as in the clitellum of an earthworm 

 at maturity. Each segment after the second bears two 

 widely separated tufts of capillaries ; all are ahke, both 

 ventral and dorsal, slightly curved, finely and simply pointed, 

 with a small flange on each side, of which one is broader than 

 the other, but in both the oblique striations are very faint. 



In the third and fourth segments they are only few in 

 number and quite short, Avhile in the fifth and following they 

 are more numerous and longer. 



The ventral surface of the last seven thoracic segments is 

 traversed by a narrow band-like ridge, about r-6th of the 

 diameter of the body, and bounded on each side by a narrow 

 furrow. This ridge is continued, though in a less marked 

 manner, on the abdomen. 



The abdominal region is marked off from the thoracic by 

 its smaller diameter ; the segments are no longer than those 

 anteriorly, but the skin is smooth, so far as one can judge 

 in the ill-preserved, soft and rather damaged condition, for 

 the sand and shelly fragments contained in the intestine cause 

 the body wall to rupture on handhng. The abdomen is 

 about 2 mm. in diameter, of uniform width over the 20 

 segments which remain, and I can see no annulations. 



The first abdominal segment, though having all the appear- 

 ance of the others, is provided with capillaries in the dorsal 

 and ventral bundles (PI. xlvii., fig. 33). 



Each of the following segments carries the usual notopodial 

 and neuropodial tori uncinigeri, in which there is a single 

 row of hooded hooks. The neuropodial torus extends up the 

 whole side of the body as a distinct ridge, and ends dorsally 

 in a free simple " gill." (PI. xlvii., fig. 32.) Above this is the 

 rounded " lateral organ," and on the dorsal surface the short 

 notopodial torus, which is not at all prominent and nearly 

 meets its fellow in the median line as in N. lineatus. 



The hook (PI. xlvii., fig. 34) has a long shaft curved like the 

 chaeta of an earthworm ; it is bent gently at its proximal end, 

 and terminates distally in the usual hook, with an accessory 

 tooth on its upper surface. The whole hook is almost en- 

 tirely enclosed in a large nearly circular hood, which is in 

 reality double (PL xlvii., fig. 35). 



