Tetillopsis longitridens
Schrammen 1910
The image shows the radiating pattern of exceptionally long (up to 20 mm) megascleres which comprise amphioxes and protriaenes (see bottom figure).
The second example is smaller, but more complete. However, the shafts of its triaenes are slightly swollen below the bifurcation while those of the first example and those shown in the figure below do not show such swellings. Hence the identification is uncertain.
Tetillopsis bears many similarities to modern members of the Family Tetillidae ("golfball sponges").
Amphiox (top) and protriaene (bottom) of Tetillopsis longitridens.
From Schrammen (1910)