. Fresh-water biology. Freshwater biology. THE SPONGES (PORIFERA) 309 19 (16) Margins of rotules serrated or incised. Ephydaiia Lamouroux. 20 Spongillidae with gemmule spicules of the birotulate type that are uniform or variable in length but not definitely of two classes, long and short, and that have finely or deeply cut margins. 20 (35, 36) Dermal spicules if present neither birotulate nor stellate. . 21 21 (22) Rays and spines of birotulates subdivided and microspined. Ephydatia subdivisa (Potts) 1887. Sponge massive, encrusting, compact. Gemmules few. Skeleton spicules smooth or microspin
. Fresh-water biology. Freshwater biology. THE SPONGES (PORIFERA) 309 19 (16) Margins of rotules serrated or incised. Ephydaiia Lamouroux. 20 Spongillidae with gemmule spicules of the birotulate type that are uniform or variable in length but not definitely of two classes, long and short, and that have finely or deeply cut margins. 20 (35, 36) Dermal spicules if present neither birotulate nor stellate. . 21 21 (22) Rays and spines of birotulates subdivided and microspined. Ephydatia subdivisa (Potts) 1887. Sponge massive, encrusting, compact. Gemmules few. Skeleton spicules smooth or microspined, abruptly pointed. Birotulates very numerous, robust, shafts frequently spined; rays short but subdi- vided. From St. Johns River near Palatka, Florida. Fig. 567. Spicules oi Ephydaiia subdivisa. Three tyf)es of spicules figured here: smooth and spined skeleton spicules; long, massive gemmule birotu- lates, spined and subspined; rotules of same. X lOO. (After Potts.). 22 (21) Rays and spines of birotulates entire 23 23(24) Margins of rotules very finely serrate. Ephydaiia millsii (Potts) 1SS7. Sponge encrusting. Gemmules small. Skeleton spicules nearly straight, slender, rather abruptly pointed, entirely microspined. Gemmule birotulates very numerous, very symmetrical, their shafts usually smooth. Rotules sometimes microspined. From Sherwood Lake, near Deland, Florida. Fig. 568. Spicules of Ephydaiia millsii. Three types of spicules figured here: microspined skeleton spicule; mature gemmule birotulates with smooth shafts: probably immature forms with less notching on the rotules: face of rotulates lacinulate or dehcately notched, and without rays. X loo. (After Potts.). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Ward, Henry Baldwin, 1865-1945; Whipple, George Chandler, 1866-1924. joint author. New Yo
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
