OCR Text |
Show 1896.] FROM THE SANDWICH ISLANDS. 209 of the ventral couple. The spermathecal pores have a position corresponding to that of the glands. As to internal anatomy, I could find no well-developed gizzard ; this, if present, is certainly rudimentary. The intestine appears to begin in the xvith segment. The last heart is in segment xii. The sperm-sacs, very racemose in character, are in segments xi., xii. The spermathecce are in segments viii., ix. Each is an oval pouch with two diverticula of the same form, but smaller, one on each side. The spermiducal glands are not very long and but slightly coiled. There were two fully developed penial setae in the bundle which I extracted for examination, and four immature ones. The fully mature setae are ornamented upon the distal one-fourth by sparsely scattered triangular, often rather blunt and not very large tubercles. These were also apparent upon all the immature setae. Hab. Macquarie I., S. of N e w Zealand'. Remarks.-It will be obvious from the above description that the present species cannot be possibly confounded with any N e w Zealand species, with which it would be natural to compare it in the first place. There are in N e w Zealand no members of the genus Acanthodrilus (s.s.) which present the following combination of characters :-Setae distant, gizzard rudimentary, clitellum short (xiii.-xvi.), nephridia not alternating, spermathecae with two diverticula. Acanthodrili with these characters are restricted in range to Patagonia, S. Georgia, and the Falkland Islands. The Patagonian group thus characterized contains four species, viz., A. bovei, Bosa, A. georgianus, Mich., A. falclandicus, F. E. B., and A. aquarum dulcium, F. E. B., which furthermore agree in being all of small size. The only difference which distinguishes A. macquariensis from these is the form of the penial setae and the position of the genital papillae. It is a most interesting fact, and one which has an obvious bearing upon the theory of a former northward extension of the Antarctic continent, that from Macquarie Isl., 600 or 700 miles south of N e w Zealand, and therefore so much nearer the existing southern continent, a decidedly Patagonian and South Georgian form of Acanthodrilus should have been met with. BENHAMIA INDICA, n. sp. (Fig. 3, p. 210.) I have received from Mr. Wroughton, through the kind suggestion of M r . E. H . Aitken, a number of worms which may belong to a new genus. They are stoutish worms, the largest reaching a length of three or four inches. The prostomium is large, but does not encroach upon the buccal segment. The setae of the ventral couple are fairly closely approximated to each other, those of the dorsal couple are distant. The space 1 I am indebted to Prof. T. J. Parker, F.R.S., for the specimens. PROC. ZOOL. Soc-1896, No. XIV. 14 |