2 literature references for Synops anceps Vosmaer, 1894:

Author: Van Soest, R.W.M.
Year: 2001
Title: Porifera, in: Costello, M.J. et al. (Ed.) (2001).
Source: European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification. Collection Patrimoines Naturels, 50:
Author: Vosmaer, G.C.J.
Year: 1894
Title: Preliminary notes on some tetractinellids of the Bay of Naples.
Source: Tijdschrift der Nederlandsche Dierkundige Vereeniging (2) 4: 269-286.