284 DISCOVERY REPORTS 



Gizzard large, cylindrical, in segment 6, not in segment 8 as described by Beddard 

 for the types of this species. Salivary glands extend into segment 5. Intestine widens 

 rather gradually from segment 17. Typhlosole absent. Lateral hearts, last pair in 

 segment 12. Nephridia: the wide tube is L-shaped and the short limb of the L near the 

 external opening is dilated to form a terminal vesicle. Ovaries very large, as originally 

 described by Beddard. Ovisacs absent. 



Seminal vesicles comprise two unusually small pairs in segments 9 and 1 1 respectively, 

 not one pair in segment 1 1 as described for the types. Prostates occupying four seg- 

 ments each; the gland thick, tubular and coiled in one plane, beginning in the first 

 prostatic segment; duct confined to the first prostatic segment, very thin, moderately 

 long and coiled, sharply separated from the gland. 



Penial setal sac muscles originate from the body-wall at the third intersegment behind 

 the prostatic pores. Penial setae in two similar sub-bundles ; the form of the seta is 

 essentially in agreement with Beddard's description for the types. The ornamentation is 

 as later described by Michaelsen (1. c), except that the fine rows of teeth are not con- 

 fined to the convex side of the curvature at the distal end but occur on both sides 

 (Fig. 2 i). Below the flattened blade the setal stem is thickened. Dimensions, length 

 ca. 2 mm.; diameter near base 31 /li {b), ca. 42/i {a)\ in middle of stem 26-27^ (/»), 

 28-29;^ (a), in thickened region below blade 31-32/Lt (a), 35/x (h)\ thickness of blade 

 I5-5/X narrowing to 'j-^ii- for both setae, breadth of blade ca. 34/u. (only an a measured 

 in face view). 



Spermathecae as described for the types (Fig. 3 c, d). 



In other characters essentially in agreement with previous descriptions. 



Observations. This species is exceedingly close to Y. diversicolor (Bedd.) from which 

 it was distinguished by Beddard by the form of the prostomium. The present specimen 

 agrees with the description of Y. diversicolor, and differs from Y. gracilis in the position 

 of the gizzard and in the presence of seminal vesicles in segment 9 ; the prostomium is, 

 however, epilobic. Michaelsen expressly states that the penial setae of the two species 

 are identical and in view of this it seems probable that these species are really synonymous 

 or at any rate merely represent forms or subspecies. In the absence of further evidence 

 the present specimen is referred to Y. gracilis, which has priority. 



Yagansia papillosus (Bedd.) (Figs. 2 g, h, 3 b). 



Microscolex papillosus, Beddard, 1895, Proc. Zool. Soc. London, 1895, p. 230. 



Microscolex papillosus, Beddard, 1896, Ergeb. Hamb. Magalh. Sammelr., Naid. Tubif. Terric, 



p. 50, figs. 1-4. Hamburg. 



Yagansia papulosa, Michaelsen, 1899, ibid., Terricolen (Nachtrag), p. 23. 



Y . papulosa, Michaelsen, 1900, Das Tierrcich, x, Oligochaeta, p. 161. 



St. 222, St Martin's Cove, Hermite Island, Cape Horn, 23. iv. 27, under logs and stones; one 

 clitellate specimen, in poor preservation. 



Colour slightly pigmented dorsally at the anterior end. Prostomium epilobic. 

 Clitellum extends over about 13-16, saddle-shaped, extending laterally to setal line b. 



