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Show 670 MR. F. E. BEDDARD ON NEW [Dec. 20, present and quite normal; on segments xvii. and xix. the ventral-most seta is present and unmodified. Octochcetus antarcticus is furthermore remarkable for the fact that the setae of the xviith and xixth segments appear at first sight to be present and normal; as a matter of fact, the outer seta of the ventral pair is replaced by the penial setae, which occur exceptionally in this species : these setae are very much smaller than in Acanthodrilus dissimilis for example, and can hardly be seen until they are examined microscopically, but they are undoubtedly there. The ventralmost seta of the ventral pair is not absent from these segments as it usually is, but is quite recognizable; this species is therefore in a less modified condition than is any other of the species of Octochcetus, or Acanthodrilus, or Benhamia. In A. annectens and A. paludosus, described in the present paper, there is, as in Octochcetus, a single seta ventrad of the atrial pores. In all the species of Benhamia which I have dissected, the calciferous glands are different from those of Acanthodrilus or Octochcetus. These glands are (in Benhamia) reniform pouches attached to the sides of the oesophagus; in Acanthodrilus and Octochcetus these glands present the appearance of swellings upon the course of the oesophagus. Moreover, in Benhamia there appear to be always three pairs of calciferous glands which may, perhaps, prove to be always in segments xv., xvi., and xvii.; they have been for the most part described as in these segments, and it is possible that in those cases (e. g., B. biittikoferi, Horst) where they are stated to occupy the xivth, xvth, and xvitb segments, a mistake of one segment may have been made; anyhow the three pairs seem to be characteristic, and nearly, if not quite, universal. In the two species of Benhamia which I describe in the present communication, the spermatothecae have a peculiar form, which is indicated in the accompanying drawing (Plate XLVI. fig. 7 ); the pouch is constricted in the middle, the constriction not coinciding with the attachment of the single diverticulum. Michaelsen has figured the spermatotheca of Benhamia stuhlmanni1, which shows precisely the same structure, but does not remark upon it in the text of his paper. This peculiar form of spermatotheca is not, however, found in all the members of the genus Benhamia, for Horst figures the spermatothecae of Benhamia beddardi as like those of the genus Acanthodrilus2. For the purpose of comparison I subjoin a definition of Benhamia ;- Benhamia, Michaelsen. Prostomium sometimes continued by grooves on to buccal segment ; clitellum xiii. (xiv.)-xix. (xxii.); setce strictly paired; two gizzards in vi., vii., or vii., viii. ; calciferous ylands three pairs in xiv.-xv-xvii. ; nephridia diffuse ; dorsal vessel sinyle ; penial setce nearly 1 " Beschreibung der von Herrn Dr. Fr. Stuhlmann im Mundungsgebiet des Sambesi gesammelten Terricolen," JB. Hamb. wiss. Anst. vii. Taf. i. fig. 8. 2 "Descriptions of Earthworms.-IV. Acanthodrilus beddardi, n. sp., a remarkable Earthworm from Liberia," Notes Leyd. Mus. vol. x. pi. vi. fig. 1. |