Illustrated guide to the echinoid (Echinodermata: Echinoidea) fauna of South Africa Author Filander, Zoleka Author Griffiths, Charles text Zootaxa 2017 4296 1 1 72 journal article 32399 10.11646/zootaxa.4296.1.1 ad746972-3837-4f1d-bf97-c09e5d7f1bd5 1175-5326 843325 EFE86EDD-D170-4D97-87D9-3125400713EC Sperosoma biseriatum Döderlein, 1901 Fig. 20 A–C. FIGURE 20. Sperosoma biseriatum A . Map showing distribution. B . Aboral view of preserved specimen (Schultz, 2010). C. Oral view of preserved specimen (Schultz, 2010). Sperosoma biseriatum : Döderlein, 1906 : 150 –153. Pl. XIX, Fig. I. Pl. XL, Fig. I; Mortensen, 1935 : 191 –193. Pl. XI, Figs 1–2 . Pl. LXXVI, Fig. 13 ; Clark & Courtman-Stock, 1976 : 221 ; Schultz, 2011 : 1102 , Figs 1930–1931 . Echinosoma petersii : H.L. Clark, 1923 :375 ; 1924:5. Material examined. None, entry based on the literature. Identification. Preserved test fragile, with irregularly arranged tubercles, larger tubercles restricted to ambitus. Pore-pairs in oblique/horizontal arcs, forming three ventral series. Preserved specimen reddish-brown. Global maximum size. Maximum test diameter 120 mm . Global distribution. East Africa and Arabian Sea , East coast region of South Africa , at 800–1020 m depth ( Clark & Courtman-Stock 1976 ). Remarks. Mortensen (1935) reports on specimens from the “ South African Marine Survey ” but neglects to give locality data. Record of species in Natal is based on Mortensen (1935) suspecting Clark’s (1925) Echinosoma petersii entries to be S. biseriatum ( Clark & Courtman-Stock, 1976 ) . Unfortunately, there is no specimen of this species in the Iziko Museum, thus we were unable to verify this record. Differs from Hygrosoma petersii in that the tubercles diminish in size towards mouth, rather than totally disappearing.