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Show 678 MR. F. E. BEDDARD ON N E W [Dec. 20, The gizzard lies in segments v. and vi., but only one-fourth of the organ lies in the anterior segment. Calciferous glands are, as in A. annectens, totally absent; the intestine begins in the twentieth segment. Some of the septa are thickened. There is a mucous gland, and the nephridia are paired. The gonads are normal in position ; they are not situated on the posterior face of their segments as is the case with A. annectens. Opposite to them are the funnels of the ducts, which are like those of other species and occupy the same segments. The sperm-ducts, however, agree with those of A. annectens to differ from those of most other Earthworms, in running within the thickness of the body-wall ; they retain their individuality until just before the external aperture. The atria have no peculiarities of structure; there are no penial setae ; strong muscular bands run from the lateral to the ventral parietes in the neighbourhood of the atria, a character which unites this species and Acanthodrilus annectens to the genus Octochcetus: the presence of these muscular strands is perhaps to make up for the absence of penial setae; the atrial papillae can possibly be considerably protruded by their means, and as they (the extruded papilla?) are tapered at the extremity, they can, it is likely, be actually inserted in the spermatothecal orifice and convey the sperm direct. The oviducal pores are placed just in front of the ventralmost setae. The oviducts have no egg-sacs attached to them. The sperm-sacs are in segments ix., xi., xii.; I could not find any sac in the intervening segment. The spermatothecae are, as in all the Acanthodrilidae (excepting only A. communis), two pairs and lie in the usual segments, i.e. viii., ix.; each pouch has, as in Acanthodrilus annectens, more than one diverticulum ; in the present species there are two, one of which is rather the larger. Closely allied to Acanthodrilus annectens as this species undoubtedly is, there will be no difficulty in distinguishing it. The chief points of difference are :-(1) position of gizzard; (2) normal position of gonads ; (3) form of spermatothecae. 5. Acanthodrilus falclandicus, n. sp. Some time since I added1 some anatomical details to Michaelsen's account of Acanthodrilus georgianus2, which had been derived from the study of what I believed to be an identical form. More recently Michaelsen 3 gave reasons for regarding the species described by myself as not identical with that named by him Acanthodrilus georgianus. Dr. Michaelsen has been so good as to send me two specimens of his A. georgianus, and I have therefore been able to follow the account, which be has given regarding the species. 1 " Contributions to tbe Anatomy of Earthworms, with descriptions of some new Species," Q. J. M. S. vol. xxx. p. 421. 2 " Die Oligochaeten von Siid-Georgien &c," JB. Hamb. wiss. Anst., Bd. v. p. 68. 3 " Oligochaeten des Hamburger naturhistorischen Museums, iii.," JB. Hamb, wiss, Anst. vii. p. 7. |
