Ircinia strobilina is a species of sponge in the family Irciniidae. It is grey or shiny black in colour, with spiny structures (conules) dotting the surface. The spiny structures are interconnected by ridges, though not arranged in an orderly lattice. This species is globular and massive in shape, but usually no more than 0.3 metres (1 ft) across. I. strobilina is lobed and spherical and has a tough consistency. The large excurrent pores are located in depressions at the top of the sponge. Many smaller incurrent pores are scattered across the surface, more densely at the sides.