Redescription of two species of Cymbasoma from southwest Britain and from Indonesia (Copepoda: Monstrileoida), with notes on taxonomy

One of the main current problems in the taxonomy of the monstrilloid copepods is the lack of detailed descriptions. Most of these descriptions are poorly illustrated making the recognition of species even more difficult. Reexamination of specimens deposited in different museums of the world has vielded new taxa but also the opportunity of redescribing these species according to upgraded standards. Two species of Cymbasoma, one from southwest England and the other from the Java Sea are redescribed from the holotype specimens following upgraded standards. Both species are compared with related forms for the first time. The former species (C. striatus) has several interesting characters of which the most important is a fringe of striations covering about half its cephalothorax. The other one (C. javensis) is herein transferred to the genus Cymbasoma by having a urosome with two free somites posterior to the genital complex. It shows previously unreported and unique characters such as the basal ornamentation of two antennular setae, and most importandy, a set of four paired postantennular structures which may represent remains of oral appendages which were supposed to be lost in the entire group.