Monograph of British Sponges, vol. iii. pl. xxxix.-xl. For revision of nomenclature in this Monograph, see Hanitsch, Tr. Liverp. Biol. Soc. viii. 1894, p. 173.
Journ. Physiol. ix. 1888, p. 1.
Sollas, Ann. Mag. Nat. Hist. (4) xx. 1877, p. 285; Bütschli, Zeitschr. f. wiss. Zool. xix. 1901, p. 236.
Minchin, "Sponges" in Treatise on Zoology, edited by E. Ray Lankester, p. 87. See also Bidder, Proc. Roy. Soc. li. 1892, p. 474.
Zool. Jahrb. Anat. vii. 1894.