Fresh-water biology. Freshwater biology. THE SPONGES (PORIFERA) 307 7 (8) Tubules of gemmules turned upward or outward from the groups. Spongilla fragilis Leidy 1851. Sponge encrusting in subcircular patches, thin at
Fresh-water biology. Freshwater biology. THE SPONGES (PORIFERA) 315 SO (48, 49) Foraminal tubule still shorter; tendrils, three to five, very long and slender Carterius tenosperma Potts 1880. Sponge forming irregular masses
Fresh-water biology. Freshwater biology. Sponge massive, though brittle and friable. Slieleton spicules slender, smooth, sharply pointed at both ends, nearly straight. Shaft of long birot- ulates almost smooth, slender, straight; rotules