segments. I found as many as four setæ in two of the bundles, and, according to the accepted theory respecting this genus, the setæ should always be in even numbers (2, 4, 6, 8); but the rule is by no means invariable. In one specimen the four posterior segments were without setæ, and the penultimate set of four had only one seta in each sac. A marked peculiarity of this species is to be found in the colour of the blood, which is decidedly disposed to be red, as may be seen when the worm has been kept for a day or two in clean water. The body segments are striate, with about half a dozen rows of striate cells per segment. The girdle extends over segment xii and the hinder half of segment xi, the usual glandpores being found on the former segment. I traced the dorsal blood-vessel to segment xviii, so it is post-clitellian in origin. The egg-sac extended back to the sixteenth segment. The blood-vessels in segments i-iv did not differ greatly in arrangements from that which usually prevails, the dorsal vessel giving off two branches on each side in the third segment, which formed loops and joined the returning vessels caused by the dorsal vessel dividing into two at the head. I found heart-like swellings in segments vii, viii, ix. The brain is nearly as broad as long, convex behind, and very slightly concave in front, the outline being slightly oval rather than circular. The coiled tube of segment xi is very long and fine; but the most obvious characteristic is found in the spermathecæ. There is a pair of sacs at the base of the pouch which is attached to the intestine, and at the outer extremity, between segments iv and v, the aperture of the spermathecal tube has a pair of large brown glands. These are so conspicuous that when first seen they have all the appearance of eye-spots. The length of the tube is about three times the width of the sacs.
I have named the species magna, because it is by far the largest yet described. I have not studied the nephridia, nor have I as yet determined the salivary glands, for want of material. The worm, which is sluggish in its habits, is found in moist places by slowly moving water. I found the same worm, or a close ally, at Hastings last summer, but, as only one specimen was taken, and one's holiday equipment does not render identications easy, the exact species was not determined.
