ENCHYTRAEIDAE 249 



A copulatory gland, small and asymmetrical, is present in segment xiv, and another, 

 still smaller, in xiii. 



In 1905 Michaelsen described (1905 a) from Kerguelen Island (in the southern part of 

 the Indian Ocean) a dorsally and laterally pigmented worm which he named Marionina 

 werthi. The chief characters were: a maximum number of 10 setae per bundle; testes 

 (apparently of small size) consisting of a small number of separate cord-like lobes 

 (i.e. "divided"); funnels probably about five times as long as broad; penial body 

 bulbous, small, embedded in the body-wall ; a single prostate ; spermathecae broadly 

 spindle-shaped, no distinct duct, no glands ; copulatory glands in xiv, extraordinarily 

 large, extending upwards towards the dorsal surface. 



In 1922 Benham (1922) discovered amongst the worms collected on Macquarie 

 Island (to the south of New Zealand) similarly pigmented specimens, which he sup- 

 posed to belong to Michaelsen 's species, and which he therefore did not describe fully, 

 contenting himself with giving the points in which they differed from the latter author's 

 description. Thus they had a maximum of 13 setae per bundle; the prostates were 

 "some in front of, and others behind the sperm pore" (they are shown in the figure as 

 in two groups, an anterior and a posterior, opening independently of each other and of 

 the vas deferens) ; no penial bulb ; the spermathecal ampulla considerably wider than the 

 duct, from which it is distinct ; two gland masses opening into the ectal end of the duct. 



M. grisea, from the Palmer Archipelago, described on p. 243, has much the same 

 pigmentation as the two foregoing groups of specimens (apparently less pigment is 

 present on the ventral surface of the anterior segments) ; the maximum number of setae 

 per bundle is 8 ; the testes are large, and show a commencing cleavage into lobes like 

 those of Lumbricillus; the funnels are 3-3 i times as long as broad; the prostates are two 

 on each side, anterior and posterior; the penial bulb is of small size, not distinctly 

 encapsuled, somewhat indefinite in its limits, and mostly contained within the body- 

 wall ; the spermathecal duct is bulbous in form, broader than the ampulla, and has two 

 glands associated with it; the copulatory glands are in xv, and do not reach the level 

 of the intestine ; there is a thickened ventral plate of epithelium in segment x. 



Finallv M. oestumn, from South Georgia, has the same pigmentation as the last ; the 

 maximum number of setae per bundle is 17 ; the testes are small, and consist of a small 

 number of separate cord-like lobes ("divided"); the funnels are 2\ times as long as 

 broad ; the prostates are much as in M. grisea ; a penial bulb can scarcely be described, 

 but a large spongy muscular mass envelops vas deferens, stalks of prostates, and a group 

 of gland cells ; the spermathecal apparatus is tubular, and the duct distinct, broader than 

 the ampulla, associated with two gland masses; copulatory glands in xiii and xiv, small 

 or very small ; no ventral plate in x. 



We may first compare Benham's worms with M. werthi. Benham implies that the 

 structural differences between his specimens and Michaelsen 's are sufficiently great to 

 justify their separation as a distinct species — or at least would be so, were it not for the 

 similarity of pigmentation ("were it not that the pigmentation is so unusual I should be 

 inclined to make a new species for it"). Thus in M. werthi the spermathecal apparatus 



