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Show 212 MR. F. E. BEDDARD ON [Mar. 3, view of the viscera seen 011 cutting open the body-wall in the dorsal median line. No such figure of the anatomy of this genus has been published up to the present; and it is convenient to show the relations of the different organs and their comparative sizes. There are points in the anatomy of the genus Stuhhnannia which are illustrated by that drawing, and to which attention does not appear to have been called. The last pair of hearts lies in the eleventh segment, as in so many other Eudrilids, for instance in the genus Polytoreutus ; and the septum which should separate segments xiii. and xiv. is nearly missing. 1 am disposed to associate this latter fact with the presence of the ccelomic sacs surrounding the gut, which may have been developed at the expense of the septum, as in Eudrilus', in which genus the corresponding septum is also much reduced. Another matter- to which I would wish to direct attention, is the existence of intestino-tegumentary trunks, which have not yet been recorded in this genus. They are, of course, of wide occurrence among earthworms. A further point of some little interest is visible in the sketch exhibited herewith. In my ‘ Monograph of the Oligocheeta,' J I pointed out the existence of at least occasional asymmetry of the female reproductive organs shown in the presence of only a single receptaculum ovorum, that of the opposite side of the body being absent. In other specimens3 I found precisely the same state of affairs. The species that I examined was, I believe, Stuhhnannia variabilis. In the present species of Stuhhnannia there is exactly the same asymmetry, the receptaculum being only present upon one side, and that the right. Or, to be mor e accurate, the receptaculum is possibly present also on the left side, but is quite rudimentary, and, i imagine, functionless. The " Eitrichterblase," as Michaelsen has termed it, is present on the left side, and is simply a loop of the oviduct, the two sections of the tube running in close contact side by side; just opposite to it is a small spherical projection. A lumen is present in this, which is the rudimentary funnel, but the lumen is no wider than that of the oviduct elsewhere, and there is no question of any free communication with the body-cavity outside; there was no break to be detected in the muscular wall of this projection, which perhaps should be regarded as funnel receptaculum. A series of sections through the rudimentary funnel and the adjoining parts of the oviduct confirms the appearances displayed in a preparation mounted in glycerine. The rudimentary funnel (or funnel -f receptaculum) is but a slight protuberance, which is traversed up to its very end by a blindly ending branch of the 1 Beddard, " O11 the Gonad Ducts and Nephridia of Eudrilus" P. Z. S. 1902, vol. ii. p. 89. 2 Oxford, 1895, p. 602. 3 " On some Earthworms from British East Africa, &c.," P. Z. S. 1901, vol. i. p. 355. |
