MEGASCOLECIDAE 275 



Microscolex georgianus, f. georgianus (Mich.) (Figs, i c-f, T,a). 



Acanthodrihts georgiamis, Michaelsen, 1888, Jahrb. d. Hivnb. Wissensch. Anst., v, 1887, p. 68, 



pi. 2, fig. 4 a-d. 



Mundane georgiana, Michaelsen, 1889, ibid., vi, 1888, p. 61. 



Acanthodrilus georgianus, Michaelsen, 1890, ibid., vii, 1S89, p. 57. 



Notiodrilus georgianus, Michaelsen, 1899, Zool. Jahrb., Syst., xii, p. 239. 



N. georgianus, Michaelsen, 1900, Das Tierreich, x, Oligochaeta, p. 130. 



Microscolex {Notiodrilus) georgianus, Michaelsen, 1905, Deutsch. Siidpolar-Exp. 1901-3, Oligo- 



chaeten, ix, Zool., i, p. 54. 



Microscolex georgianus, Michaelsen, 1905, Wiss. Ergeb. d. Schwed. Siidpolar-Exp. 1901-3, v, 3, 



p. II. Stockholm. 



nee Acanthodrilus georgianus , Beddard, 1890, Quart. Journ. Micr. Sci., N.S., xxx, 4, p. 421. 



In earth half-way between Cairn and Maiviken, St. MS 70, South Georgia, 4. iii. 26; three 

 clitellate and three non-clitellate semi-mature specimens. In wet moss 200 ft. above Upper Lake, 

 St. 122, South Georgia, 14. xii. 26 ; four fully or partly clitellate and six non-clitellate semi-mature or 

 immature specimens. Under stones near Upper Lake, St. 122, South Georgia, 14. xii. 26; five fully 

 or partly clitellate, seven non-clitellate semi-mature and one immature specimen, one damaged 

 anterior end and two posterior ends. Moss and Acaena, Larsen Harbour, South Georgia, 6. i. 27; 

 seven clitellate and one immature specimen. River bank, Wilson Harbour, South Georgia, St. WS 

 62, 19. i. 27; fourteen clitellate, seven non-clitellate semi-mature and one immature specimen, and 

 four fragments. From river bank. Undine Bay, South Georgia, St. 65, 22. i. 27; eighteen fully or 

 partly clitellate specimens. Cumberland Bay, South Georgia, no date; twenty clitellate and semi- 

 mature, nine immature specimens, in very poor preservation. 



External characters. Length rather variable, 31-80 mm. Colour: usually tinged with 

 reddish pigment dorsally at the anterior end, frequently very faint or absent, occasionally 

 moderately deep. 



Prostomium epilobic, with or without a cross-furrow ; the extent of the tongue is very 



variable, in some specimens being almost tanylobic. CHtellum -13- -16, usually 



extending laterally to about setal line « ; in a few specimens the line of demarcation is 

 indefinite and the clitellum appears to extend ventrally on to segments 14 and 15. 

 Copulatory papillae very variable, occasionally absent, frequently paired or single on 

 one or other side on posterior border of segment 10 in the line of the ventral pair of 

 setae ; papillae are usually present, ventrally or laterally, in the region of segments 16-19, 

 variously disposed either on the borders of the segments or across the intersegments. 

 Dorsal pores absent. Nephridial pores about ^ be below setal line c on the anterior 

 borders of the segments. Spermathecal pores, two pairs in setal line b at intersegments 

 7/8 and 8/9, either on conspicuous papillae or inconspicuous; this is apparently not 

 correlated with the degree of maturity. Female pores one pair on segment 14 in front 

 of seta a on each side. Intersetal ratios very variable ; in some specimens cd may be about 

 equal to ab as described for the types, but more usually cd is greater than ab. In general 

 the ratios are more or less similar to those of M.falclandicus ; this character is in any case 

 too variable to be relied on in distinguishing the two species. 



The other external characters are essentially as described for the type. 



