POLYOH^ETA BENHAM. 107 



below, and so probably represents six segments; of these glands the three anterior 

 extend further round the body than do the other three. The body terminates as usual 



in an anal funnel. 



The uncini commence on the 5th segment, and the neuropods of the last seven 

 segments are very prominent. 



In the 2nd, 3rd, and 4th segments there are one or two short, stout, bluntly- 

 pointed spines below the small bundle of capilliform chaetae : Gravier in speaking of these 

 says that there is " une rang e de crochets ventraux "; if by this he means a vertical 

 row of hooks the statement does not apply to these specimens. 



The " head," i.e., the prostomium and peristomium, is equal in length to the 2nd 

 segment ; each of the next five segments is approximately equal to this; but each 

 of the following six is a good deal longer. But it depends on the state of preservation, 

 for in some extended worms this difference between the first five and the next six is 

 hardly noticeable. The chsetae in this genus are inserted near the anterior boundary of 

 the segment; in the first five, at about one-third ; in the following six or more, at 

 about one-fourth the length of the segment. 



There is a glandular band surrounding the prechaetal region of each segment, 

 this is interrupted on each side by a deep, narrow, horizontal furrow. This glandular 

 band forms, in some individuals, a feeble collar, but in extended specimens the overlap 

 is not apparent. At the segment on which the true hooks appear, namely, the 5th, 

 there is also a post-cheetal gland ; at first this is narrow, but as the series of uncini becomes 

 longer this gland increases in width as well as in length. By the 8th segment the pre- 

 chsetal band is differentiated into a narrow dorsal and a wider ventral portion; and the 

 ventral gland, which now appears as a large oval patch, overlaps the previous segment 

 more distinctly. By the 10th the dorsal gland has become considerably reduced, and 

 on the llth has disappeared, so that posteriorly only the ventral or uncinal gland 

 persists ; this enlarges in the segment further back, till in the 17th, for instance, it covers 

 half its length. 



I have given these details as Gravier says nothing about them; the arrangement 

 is entirely in agreement with the general character of the glands described by Arwidsson 

 for the genus. 



Gravier's account of the prostomium, or cephalic plate, needs no addition, though 

 his figure is somewhat diagrammatic. The dorsal transverse portion of the membrane 

 that surrounds the plate is crenated. He states that there is a dozen low rounded lobes, 

 but I find that the number and form is variable. Sometimes they are uniform in size, 

 though in some individuals they may be larger than in others; in the former case I 

 counted 18 lobes, in the latter as many as 25. In other individuals, the smaller and 

 larger lobes are irregularly alternating. 



The anal funnel, as the generic name implies, is surrounded by uniform digitations, 

 of which I count as many as 36. 



