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Show 162 MR. F. E. BEDDARD O N W O R M S [Feb. 16, The male pores are upon segment xviii., comparatively near the ventral median line ; they are not, as is, for example, the case with Perichceta affinis, at the sides of their segment. The setae of segment xviii. are present between the two pores, but they cease to be visible some little way from the pores on each side. The pores themselves lie in the direct line of the circle of setae. Close to each of tbe apertures of the atria is a group of rounded orifices, which in one specimen showed the following arrangement :-There were four on one side and five upon the other, each group of pores lying in a circle below, and to the inside of, the atrial pores. The arrangement therefore, as well as the number of these pores, shows some differences from Perichceta aspergillum ; I occasionally observed fewer than four pores, but never anything like so many as eleven, which Perrier states to be the number found in Perichceta aspergillum. W h e n the cuticle is stripped off, these pores become very obvious and can be easily counted with a lens. Examined under the microscope they do not present the appearance of pores, but of solid papillae covered by a reticulation ; they are in fact, as I have already pointed out 1 for Perichceta aspergillum and other species of the genus, the openings of masses of unicellular glands. I could not see the spermathecal pores, and there was no development of accessory papillae corresponding to those which have just been described as occurring near the atrial pores. This is another point in which Perichceta bermudensis differs from Perichceta aspergillum, where such papilllae have been described and figured by Perrier. The gizzard occupies segments viii.-x., the septa of those segments being absent; the remains of the septa are to be recognized in a series of ligamentous bands which attach the gizzard to the parietes ; of these there are three pairs : two on each side are attached, close to each other, not to the gizzard itself, but to the septum which lies just in front of it; they pass obliquely backwards and outwards ; behind these and nearly at the posterior extremity of the gizzard is another band on each side. The walls of the oesophagus behind the gizzard are much folded (internally) and very vascular in segments xii.-xiv., particularly in segment xiii. ; this region no doubt represents the calciferous glands of other Earthworms, which do not here form distinct diverticula. In segments v. and vi. are " blood-glands" which present a racemose appearance. The intestine is provided with the usual pair of caeca. The spertn-sacs are in segments xi. and xii. The curved duct of the atrium opens directly on to the exterior, and not through a dilated terminal portion ; it is surrounded by innumerable small white glands, which correspond to the pores which surround the external orifice of the atrium. The ovaries are in segment xiii. 1 " Contributions to the Anatomy of Earthworms, with Descriptions of some New Species," Q. J. Micr. Sci. vol. xxx. p. 461 et seq. pi. xxix. figs. 3, 4, 5. |
