Theonella Gray, 1868

Hall, Kathryn A., Ekins, Merrick G. & Hooper, John N. A., 2014, Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867, Zootaxa 3814 (4), pp. 451-477 : 464

Key to those species of Theonella Gray, 1868 , which lack desmas and other megascleres

1a. Encrusting species, forms thin sheets which cement detritus; desmas absent; megascleres absent; microrhabds very small, ~ 15 µm in length (ranging from 7 to 21 µm)................................................................... 2.

1b. Encrusting species, forms thin sheets which cement detritus; desmas absent; megascleres absent; microrhabds large, conspicuous, ~ 38 µm in length (ranging from 18 to 52 µm).............................................. T. maricae n. sp.

2a. Thin sheets cement exclusively Tenagodus shells into discrete clumps; microrhabds slender, usually curved, sharply hastate at ends, spines conspicuous, long, sharp.......................................................... T. deliqua n. sp.

2b. Thin sheets cement a variety of detritus, including quartz sand, foraminifera, algae and coral fragments; microrhabds robust, generally straight, rounded at ends, spines small, blunt, numerous.... T. xantha ( Sutcliffe, Hooper & Pitcher, 2010) n. comb.