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Show 384 MR. F. E. BEDDARD ON TWO [Apr. 17, In the middle region of the body the nephridia form a denser coating of the parietes than I have before noticed in any worm with plectonephric excretory organs. Alimentary Caned.-The pharynx of Millsonia rubens ends with the fourth segment; in each of segments v. and vi. is a strong gizzard which measures about 7 m m . in length and not less in breadth. The two gizzards are separated by an interval of soft walled oesophagus. Calciferous glands are present and show a rather unusual appearance. There are three pairs of them, which lie in segments xv., xvi., and xvii. These segments, be it noted, are the same in which the calciferous glands of the Acanthodrid genus Benhamia lie. I have already pointed out that another Crypto-drilid, viz. Microdrilus, is distinguished by the same position of its calciferous glands. These glands in Millsonia rubens have a very remarkable appearance; the surface is so much furrowed as to give them the look of a small though highly convoluted mammalian brain. In microscopic examination they are seen to present the characters usually found in these glands; the interior is occupied by numerous long folds of the lining epithelium, whose cells are rather flattened. The intestine begins in segment xviii. This part of the gut is most remarkable for a long series of caeca, which I have already referred to as a character of the genus. I counted altogether 32 pairs of these caeca, which begin at about the 28th segment. They begin aud end abruptly ; the first pair and the last are neither larger nor smaller than those which precede and follow them. The shape of the caeca is precisely that of the caeca of the genus Perichceta. They taper gradually towards the free extremity and are in fact exactly like the finger of a glove. The length averages some 6 m m . In the region of the intestine occupied by these caeca, the dorsal blood-vessel gives off in each segment two equi-sized trunks ; one of these--the most anterior-is entirely concerned with the blood-supply of the caecum of its side. The other supplies the walls of the intestine and appears not to run over the caecum ; in the section of intestine in front of the region where the caeca are I only noticed a single pair of intestinal trunks in each segment. It will be understood that these caeca are entirely metameric in arrangement-that is to say, there is a pair to each segment; they arise at first more laterally in position, afterwards their origin is nearer to the dorsal line. Reproductive Organs.-There are two pairs of testes and of sperm-duct funnels, which occupy the usual segments, i. e., segments x., xi. The sperm-sacs are in segments xi., xii. attached to the front walls of these segments; the sacs are not particularly large and do not stray beyond their segments. The spermiducal glands lie entirely within the xviith segment; they are coiled into a compact mass. The muscular duct is of a moderate length and has a nacreous appearance. I am unable to state what is the relation between the gland and the sperm-ducts. The ovaries are large and occupy the xiiith segment. There are only a single pair of spermathecae ; these lie in the viiith segment. The sacs are |
