FIGURE 4 in The genus Corvospongilla Annandale, 1911 (Porifera: Demospongiae: Spongillida) from Madagascar freshwater with description of a new species: biogeographic and evolutionary aspects

FIGURE 4. Gemmules of Corvospongilla lemuriensis sp. n. (SEM micrographs). A Gemmular cage shared by gemmules (top view) and armed by spicules (megascleres) in a dense mosaic-like layer bearing two foraminal collars; B Cage enveloping the gemmule (cross section) with megascleres and gemmuloscleres; C Gemmular theca surface with gemmuloscleres emerging at the surface (foramen not evident); D Gemmular theca surface with various morpha of megascleres and gemmuloscleres; E Micropseudobirotules (skeletal microscleres) at the gemmular surface; F Gemmular theca (cross section) tri-layered with inner layer of compact laminar spongin surrounding staminal cells, inconspicuous outer layer, and thick pneumatic layer with gemmuloscleres tangentially embedded in chambered spongin. A, B, D = specimen DTRG FW806; C = specimen DTRG FW807; E, F = specimen DTRG FW804.