Microcosmus pupa (Savigny, 1816) Cynthia pupa Savigny, 1816: 15. Microcosmus pupa: Kott, 1985: 356. Microcosmus pacificus Monniot and Monniot, 2001: 349. Distribution. The species is recorded from the Red Sea, north-east Australia, Papua New Guinea and the Philippines. Remarks. Like the present species, Microcosmus madagascariensis Michaelsen, 1918 has long spines, large oval gonads embedded in the thickened body wall, variously lobed and sometimes overlapping the gut loop on the left, and endocarps scattered on the body wall and in the gut loop. The present species is distinguished from it only by its rudimentary secondary branches of the branchial tentacles (rather than four-times branched bushy ones). Other distinctions are unclear owing to the variability in the specimens assigned to M. madagascariensis. In particular, Monniot and Monniot (2001) have drawn attention to the synonymy of M. agglutinans Hartmeyer, 1919 with M. madagascariensis which, although accepted by many authors (see Kott, 1985), remains unresolved. In considering the relationships of these species it should be noted that an Indo-West Pacific range is not unusual for species of this genus (see Kott, 1985).

Published as part of KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, pp. 1611-1653 in Journal of Natural History 37 (13) on page 1649, DOI: 10.1080/00222930110104258, http://zenodo.org/record/5260089