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Show 1901.] ANNELID OF THE GENUS ALMA. 221 A. stuhlmanni. The whole organ is very vascular; there are a pair of strong longitudinally running blood-vessels whose cut ends in a specimen from which the two penes were removed were exceedingly obvious. Besides this there is a rich network of capillaries pervading the organ ; and there are rich tufts of capillaries penetrating within the epidermis itself. There is thus quite a possibility of the organ serving, as was suggested by Levinsen, a respiratory function. The vascularity of the organ appeared to me to be more marked than in A. millsoni. In the latter species, it may be remarked, the penes are much thinner than in the present species. The penes bear setae which are apparently limited in number to two pairs, as was occasionally found by Michaelsen in A. stuhlmanni. The setae are rather slighter than those of the body generally and end in a fine point. They are nearly straight, and I could not detect any ornamentation. They are not unlike those of A. stidmanni. The setae of segments ix., x., xi., and some of the neighbouring segments to a less extent, are implanted in very conspicuous papillae, which may possibly play the part of tubercula pubertatis. They are shown in the accompanying drawing (text-fig. 59, C). I have given a somewhat full description of certain of the external characters of this species, in order to justify m y conclusion that it probably belongs to Michaelsen's species Alma stuhlmanni. That a West and an East African form should prove to be identical is a little surprising ; but less so when it is reflected that this genus Alma is at least largely aquatic. I can see at present no grounds for separating the two. The only point of difference which occurred to m e is that in A. stuhlmanni the genital setae are much smaller in proportion to the ordinary body-setae than they are in the worms from McCarthy Island. "Until the clitellum of the former is known, one cannot be quite certain. The internal anatomy could not be satisfactorily investigated owing to the condition of the specimens. I have at least shown that the subject of the present communication cannot be the same as Alma millsoni from West Africa. List of Memoirs referred to. (1) LEVINSEN.-" Om to nye Eegnormslaegter fra iEgypten." Vidensk. Medd. Kjobn. 1889, p. 31. (2) M I C H A E L S E N . - " Beschreibung der von Herrn Dr. Fr. Stuhl-mann am Victoria Nyanza gesammelten Terricolen." JB. Hamb. wiss. Anst. ix. 2, p. 8. (3) M I C H A E L S E N . - " Zur Kenntnis der Oligochaeten." Abhandl. Geb. Naturwiss. xiii. p. 7. (4) M I C H A E L S E N . - D i e Eegenwiirmer Ost-Afrikas, in Deutsch- Ost-Afrika, ix. 1896, p. 4. (5) B E D D A R D . - " O n an Earthworm of the Genus Siphonogaster from West Africa." Proc. Zool. Soc. 1891, p. 48. |
