Higgin, 1877 : 296 Iotrochota birotulata Ridley 1884 : 443 Rützler et al. 2007c : 175 Sponges of the Guyana Shelf Van, Rob W. M. Zootaxa 2017 1 1 225 6MWZ7 Higgin, 1877 Higgin 1877 [151,588,797,823] Demospongiae Iotrochotidae Iotrochota Animalia Poecilosclerida 142 143 Porifera species birotulata  Restricted synonymy:     Halichondria birotulata  Higgin, 1877: 296, pl. 14 figs 11–15.    Iotrochota birotulata;  Ridley 1884: 443; Van Soest 2002: 598, with further synonyms);  Rützler et al.2007c: 175, figs. 1–3.     Materialexamined. RMNHPor. 9940, Guyana, ‘Luymes’ GuyanaShelf Expedition, station 63, 7.5833°N 57.0667°W, depth  71 m, sandy bottom,  31 August 1970.   Description.Two ramose fragments ( Fig. 89a), each about 4 cmlong and 0.6–2 cmwide. Surface conulose, with an oscule of 3 mmin diameter. Color greyish black in alcohol. Consistency soft, fragile.  Skeleton.Thick spongin-enforced spicule tracts, 70–200 µm in diameter, cored by 20–30 spicules form a reticulation with elongately squarish meshes of 300–500 x 200–300 µm. Nospecial ectosomal skeleton.  Spicules.( Figs 89b–f) Styles, strongyles, birotules. Styles, smooth straight, with conical pointed end, occurring in a longer/thinner category ( Fig. 89b,b1), 232– 262–284 x 3– 4.6–6 µm, and a thicker/shorter category ( Fig. 89c), 178– 184–192 x 7– 9.0–10 µm. Strongyles, curved, smooth, variably in size and thickness, thicker ( Fig. 89d) and thinner ( Fig. 89e,e1) spicules about equally long, 138– 182–202 x 2– 5.4–7.5 µm. Birotules ( Fig. 89f), straight shaft, usually about 12 alae, quite uniform in size, 15– 16.2–18 µm.   Distribution and ecology. GuyanaShelf, Greater Caribbean, NE Brazil, on various bottoms at 0.1–90 mdepth ( GuyanaShelf 71 m).   Remarks.The specimen keys out in Rützler et al.’s 2007bkey as  I. birotulata, having branching habitus and possessing birotules.. 1424726521 1970-08-31 RMNH Guyana 71 7.5833 Material 7 -57.0667 143 144 1