236 PROCEEDINGS OF THE ACADEMY OF [Vol. LXXV 



The next four segments (III to VI) are similarly biannulate, 

 cylindrical, of about equal length, the posterior rings being about 

 two-fifths and the anterior three-fifths of the total length. VII is 

 a still shorter segment consisting of a setigerous ring only. The 

 following segments are reversed, the setae fascicles and tori lying 

 nearer to the caudal end; annular furrows are absent and the 

 form regularly cylindrical and about one-third longer than wide to 

 XVIII; this and the two succeeding segments being about two- 

 thirds as long as wide, uniannulate and bearing very large swollen 

 tori. The last preanal segment is still shorter, achaetous, and bears 

 a thickened region corresponding to the tori on the ventral side 

 where they merge with the base of the caudal funnel. 



The anus is located on a prominent papilla dorsal to the base of 

 the anal funnel, which is of an interesting and characteristic form 

 corresponding to the cephalic plate, but slightly more oblique than 

 the latter, the dorsal border being the more produced. A pair of 

 deep, rounded notches, contracted at the rim, divides the limbus 

 into a dorsal and a ventral lobe, the latter being again divided 

 into four prominent teeth or sublobes, two on each side, the median 

 pair triangular and pointed, the lateral somewhat curved dorsad 

 and blunt. The dorsal lobe is divided into six somewhat less 

 regular and smaller teeth, usually separated by rather shallow 

 intervals, the ventral pair broad and square with angles slightly 

 produced, the other two pair small and acute; on the medial side 

 of each of the dorsalmost is a smaller additional tooth making 

 eight in all. 



Tori and setigerous tubercles have the arrangement usual in the 

 genus and the former become relatively longer in the posterior 

 region. Somite II bears small tufts of capillary setse only. They 

 are all broken so that their characteristics are undetermined. 

 Remaining somites bear both setse and uncini. 



Many setse are broken but the following seems to be their 

 distribution and characteristics. On anterior somites they are 

 arranged in from five to nine pairs of one large and one small 

 in a short vertical line. On III and IV all appear to be of one 

 form, simple, acute, smooth, slightly bent and narrowly limbate. 

 Beginning with V, the large limbate setse are replaced by more 

 elongated and slender capillary setse, which may have a length of 

 one-third the body diameter, especially on more posterior somites, 

 but in all cases some of the smaller limbate setse remain. Most 

 of the free portion of these setse, except the extreme tip, is ornamented 

 with numerous whorls of divergent hairs or awns, always arranged 

 transversely and never spirally. So far as could be determined no 

 other kinds of setse are present. 



Uncini occur on all segments from III to XX arranged in a single 

 vertical series varying in number from 10 on III, to 28 on X, 25 

 on XV, and 19 on XX. When characteristically developed, as they 



