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Show 1901.] AND ARRANGEMENT OF EARTHWORMS. 199 seventh and the eighth segment, inasmuch as no recognizable septum divides those segments from each other. The oesophagus extends back as far as the xvth segment, in which segment the intestine commences. The calciferous glands, of which there may be said to be a single pair in this as in other species of Typhoeus, do not present the appearance of discrete pouches opening into the gut; they form an oval reddish-coloured swelling situated in segment xii. The intestine has a typhlosole ; but this is not apparent until segment xxx. (about). The characteristic intestinal glands of the genus are visible far back upon the intestine, commencing with segment lxxxiv. or thereabouts. They occupy in all five segments, and those of successive segments are separated by the septa. The dorsal vessel lies between the glands of the right and those of the left side. Intersegmental septa.-A number of septa lying in front of and behind the gizzard are thickened. In front of the gizzard are two such septa; behind the gizzard are three thickened septa. The space occupied by the gizzard-the whole of the space formed by the ccelom of segments vii. and viii.-appears to be entirely undivided by any septum or even traces of that partition. Vascular system.-The only point to which I direct attention in the structure of the vascular system is the number and the position of the " hearts." Of these there are six pairs, of which the first lie in the viiith and the last in the xiiith segment. Nephridia.-These organs consist, as in the other species of the genus, of numerous micronephridia. Reproductive organs.-The male gonads and their duct and the sperm-sacs are in this, as in other species of the genus, limited in number to a single pair. The testes and funnels lie in the xith segment, and the following one, whose capacity is thereby extended, contains the sperm-sacs. The sperm-sacs are of considerable size, measuring 6 m m . iu extreme length ; they are flattened and broad, and of a roughly triangular form, the apex of the triangle being posterior in position, the margins are somewhat lobulate. The spermiducal glands are each coiled into a tight mass, throughout which, however, the tubular structure of the gland is perfectly obvious. The muscular duct is of fair length, and its calibre is barely one third of that of the thicker parts of the gland-tube. Between the opening of the two glands the ganglionic swelling upon the nerve-cord is considerably larger than the corresponding swellings in other segments. The penial setae are rather longer than those of T. incommodus, of which a drawing is exhibited (text-fig. 57, p. 202), and they are remarkable for being apparently of a very delicate structure at the free end, which in all the setae that I have examined was much bent and in different directions. The extremity is hardly sculptured, a very fine pitting being all that is visible. The spermathecce have a longish muscular duct, to the commencement of which upon the outside is affixed a somewhat fan-shaped diverticulum. 14* |