| OCR Text |
Show 160 MR. F. E. BEDDARD ON A [Feb. 15, Nephridia.-The nephridia appear to be present in all the segments of the body with the exception of the first; they are differentiated into three series. (1) The first series consists of only one pair of nephridia ; these differ from those which follow in their structure and in their position. They lie beneath the oesophagus and are completely hidden by it; each gland consists of a flattened mass of glandular tubules, produced by the coil, which has the ordinary structure characteristic Fig. 5. One of the Anterior Nephridia. o, external aperture; /, funnel opening on to the other side of the intersegmental septum s; d, glandular vesicle. of nephridial tubules, except that the coils are more numerous. The tubule opens into a stout-walled muscular duct, distinguishable by its yellowish colour, which passes anteriorly in a somewhat sinuous course and opens on to the second segment of the body. These glands evidently correspond to the " glandes a mucosite " described by Perrier in Urochata1, and by myself in Acanthodrilus multiporus2. The funnel was very conspicuous in transverse sections. This pair of nephridia differs less from the succeeding pairs than in many other genera. The specialization of this first pair of nephridia, 1 Arch, de Zool. Exp. t. iii. 2 P. Z. S. 1885. |
