486 PROCEEDINGS OF THE ACADEMY OF [Juiie, 



sidered to represent somites IX and X, forming a transition region 

 between the 2 ends of the worm. Succeeding segments become nar- 

 rower to the anal, but increase in length to XV, beyond which they 

 gradually decrease; their form is somewhat club-shaped, being nar- 

 row anteriorly, increasing to the region of the glandular tori near the 

 posterior end, and again abruptly diminishing; in contraction the pos- 

 terior end of each probably invaginable, forming low collars in reverse 

 of those at anterior end. Somites VIII to XVIII marked laterally by 

 a series of vertical furrows and folds, which become longer caudad; 

 dorsum and venter smooth; anal and preanal somites marked by 

 circular grooves and ridges extending all around. Neural line distinct 

 for entire length, ending on margin of anal funnel between two teeth. 



Anal funnel very large, nearly eciualling widest part of body, regularly 

 bell-glass-shaped, somewhat longer than wide, margin completely and. 

 very regularly encircled by 31 short, triangular teeth of equal length, 

 two of them being double, and the mid-ventral line being an interval 

 between two teeth. Anus prominent, on a radially ridged papilla in 

 the centre of the funnel, the cavity of which is rather shallow. 



Setae are present on 19 somites, the peristomium, anal and 2 preanal 

 somites being achsetous, though the latter retain the glandular tori. 

 Setigerous tori are all situated on the sides of the ventral half of the 

 body; those for capillary setae short, rather prominent non-glandular, 

 double folds, from the cleft between which the setae appear ; uncigerous 

 tori narrow, raised ridges on first 3 setigerous somites, elsewhere glandu- 

 lar elevations cleft at the apex, becoming long, thick and prominent 

 posteriorly, and those of each pair on VI to X and XX and XXI 

 united by glandular rings. 



Capillary setae only are found on II. and both capillary setae and 

 uncini on all other setigerous somites. The largest number of the 

 former occurs on II, decreases to IV, while V to XIX bear only a small 

 but prominent dorsal fasciculus. Uncini are numerous from their first 

 appearance, and increase in number from about 20 on III to 48 on 

 somites of the posterior half, the tori having meanwhile increased to 

 3 times the length of those on III and extended so far ventrad as to 

 be separated by a median distance of less than ^ their length. 



Capillary setse pale greenish-yellow, the slender exposed portions 

 colorless with a vitreous cortex and a fibrous centre of remarkably 

 regidar arrangement, very fine, straight, tapering, acutely pointed, 

 and delicately winged on the dorsal side on all somites. 



Uncini yellow, somewhat smaller on the anterior and ventral por- 

 tions of the posterior tori, those in the latter position differing some- 



