8a. Outermost terminal caudal seta with cluster of small spines at base; anal segment with row of spines along entire posteroventral border, spines increasing in size; antennule usually of 11 segments.

8b. Outermost terminal caudal seta without spines at base; anal segment with only 4-6 spines along ventral margin, not extending to lateral margin of somite; antennule usually of 12 segments.