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Show 1892.] SPECIES OF EARTHWORMS. 685 uniting, as Perrier thought might be eventually necessary, the two genera Perionyx and Perichceta. Vaillant in thus uniting these genera errs, in m y opinion, as much on the one side as does Benham1 on the other, when he relegates the two to different families. I have recently studied four species of Perionyx-one of which I referred to some years since in connexion with the remarkable variations in structure exhibited by individuals ; the second species, of which I owe examples to the kindness of Dr. Michaelsen, has been lately described by that naturalist2 as Perionyx gruenewaldi. The specimens of the two remaining species were sent to m e some time since by the kindness of Dr. King ; they are from Seebpore. Putting together what we know from Perrier's investigations, from m y own3 4, from those of Michaelsen5, RosaG, and Bourne7, and what I have to say here with regard to this genus, we may thus define it:- Genus Perionyx, Perrier. Perionyx, E. Perrier, Nouv. Arch. Mus. t, viii. p. 126. Setce forming complete circles, present as such upon all the segments of the clitellum; male pores close together upon a depressed area on segment xviii., with a group of modified setce in some species near to each orifice; atria lob ate; spermatothecce two (or three) pairs in (vii.) viii., ix., with or without diverticula; nephridia paired; no specially thickened septa ; no cceca. The above definition of the genus may now be supplemented by a few remarks. These remarks will chiefly concern the species of the genus ; the type species, P. excavatus, has been described by Rosa as well as by Perrier, and to a more limited extent by myself. But I a m not quite certain, after comparing two out of the three species described here in addition to Michaelsen's P. gruenewaldi, as to which of them is really Perrier's P. excavatus. The worms from Manila agree very closely with Michaelsen's P. gruenewaldi. Michaelsen distinguishes his species from that of Perrier on the following grounds : - T h e pigmentation is so marked that, if P. excavatus were of the same dark violet colour above, Perrier would hardly have omitted to notice the fact: secondly, the penial setae of P. gruenewaldi appear to distinguish it from P. excavatus: thirdly, the position of the gizzard; this organ is fixed by Perrier in the twelfth segment; Michaelsen, on the other hand, 1 " An Attempt to Classify Earthworms," Q. J. M. S. vol. xxxi. p. 247. 2 " Oligochaeten des Hamburger naturhist. Mus. iv.," JB. Hamb. wiss. Anst. viii. p. 33. 3 " Descriptions of some new or little-known Earthworms, &c," P. Z. S, 1886, p. 308. 4 " Note on some Earthworms from India," Ann. & Mag. Nat. Hist. ser. 5, xii. p. 217 (1883). 15 " Beschreibung der von Herrn Dr. Fr. Stuhlmann auf Sansibar, &c.," JB. Hamb. wiss. Anst. ix. 6 " Perichetidi di Birmania," Ann. Mus. Civ. Genova, ser. 2 a, vol. vi. p. 157. i " On Indian Earthworms," P. Z. S. 1886, p. 662. PROC. ZOOL. Soc-1892, No. XLVI. 46 |