Acanthodrilinae, sensu Jamieson, 1971

Acanthodrilinae sensu Jamieson 1971a

The definition of the subfamily Acanthodrilinae sensu Jamieson (1971a) differs fundamentally from that of Gates (1959, 1972). Prostates are not only tubular but may also (rarely) be racemose and nephridia are not only holonephridia but may also be meronephridia. Unlike many acanthodrilids of Gates, the prostates usually do not discharge on segment 18 (doing so in Rhododrilus ), typically opening on segments 17 and 19, as in the type-genus. Megascolecinae with homeotic displacement of male pores may correspond with this definition but show their affinities with megascolecines in other respects. Posterior nephridia in Acanthodrilinae sensu Jamieson (1971a) lacked the median funnel diagnostic of the Dichogastrini within the Megascolecinae sensu Jamieson. The alimentary and vascular systems differed from those of the Ocnerodrilinae in some of which, as in Eukerria Michaelsen, 1935 , the male and prostate pores have the acanthodrilin arrangement. It has been shown in the molecular analysis that dichogastrins with acanthodrilin male pores must be transferred to the Acanthodrilinae and that the dichogastrin nephridial condition has arisen more than once (see below).