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Show 1890.] WORMS OF THE GENUS PERICH.ETA. 61 Nephridia. In describing the remarkable nephridia of a New-World Perichceta, P. aspergillum (10), I pointed out that probably all Perichcetce with irregular diffuse nephridial tufts-that is to say, all the species belonging to Perichceta, Anisochceta, and Megascolex, as these genera are defined in the present paper,-would prove to possess a nephridial system of the same kind as that which characterizes P. aspergillum. The pores upon the cuticle often render it possible to predict of a given Earthworm that the nephridia will be found to be dysmetameric ; after finding upon the cuticle of P. houlleti numerous pores which could be referred to no other known structure than to the apertures of nephridia, I ventured to predict that this species would be found to agree in all essentials of its excretory system with P. aspergillum. Unfortunately I have not been able to put this prediction to the proof, as the specimens of P. houlleti which I have are not in a sufficiently good state of preservation for sectionizing. The specimen of P. indica, however, I carefully preserved, and the examination of transverse, and particularly of longitudinal, sections shows that it agrees with P. aspergillum in the minute structure and in the relations of the nephridia. A dissection of the worm shows that the nephridia do not present the regular paired condition of such forms as Lumbricus ; they are represented only by minute tufts attached to the ventral body-wall, especially to both sides of the intersegmental septa. This condition of the nephridia would lead to the assumption that a microscopic investigation of the nephridia would prove the presence of numerous irregularly-disposed external pores and ccelomic funnels. I made a number of longitudinal sections in the hinder region of the body, and found that the nephridial tubes were in places perfectly continuous from segment to segment through the septa ; the external pores also had that irregular arrangement of a large number of pores per segment which is apparently to be now regarded as a very prevalent condition among Earthworms. Spermathecce. The structure of the spermathecae is illustrated in the accompanying figures (Plate V. figs. 4, 5, 6, 8). As appears to be always the case in Earthworms, the diverticula have a different histological structure from the pouch. The epithelium lining the pouch (see fig. 6) is tall and columnar. In the diverticulum, on the other hand, the structure not only differs from that of the pouch itself, but also from that of the diverticula of other species of Perichceta ; but these differences are very possibly due to immaturity in the present specimen. The diverticulum was filled (see fig. 5) with a perfectly homogeneous fluid, slightly stained by the colouring reagent used ; the epithelium lining the pouch was formed of very low cells, not in the least columnar, and hardly to be distinguished from the muscular fibres which make up the very thin walls. Glycogenic Organs. Perichceta indica is furnished with a series of curious glandular- |