LIST OF ILLUSTRATIONS. 



FISH-HATCHING APPARATUS. 



Page. 



Fig. 1.— Original form of apparatus employed in the experiments. Used May, 1881, on the 



Potomac barges ." 185 



2. — An alternate form, used in the spring of 1881 185 



3. — Original form of apparatus, in which the method for automatic separation of dead 



from living eggs was demonstrated 186 



4. — Details to illustrate hatching and transfer of shad-fry to collectors 188 



EMBRYOLOGY. 



Fig. 1. — Thread-bearing eggs of the silversides 195 



FISH-HATCHING APPARATUS. 



Fig. 1.— The outer vessel. 210 



2. — The inner vessel 210 



3. — The inner inserted in the outer vessel 211 



4. — The complete apparatus 212 



FISHES. 



FiG. 1.— The leather caip, Cyprinus carpio 241 



CONSTRUCTION OF PONDS. 



Fig. 1. — A carp pond built in a meadow 250 



2. — Sectional view of the dam of carp pond 251 



3. — Vertical and horizontal projection of embankment 253 



4. — Vertical section of embankment 254 



5.— Horizontal section of embankment 254 



6. — Horizontal section of embankment 255 



7. — Vertical section of embankment ' 256 



PACIFIC COAST CLAMS. 



Fig. 1. — Schizothoerus nuttalli Conrad 354 



2. — Saxidomug nuttalli Conrad 355 



3. — Glyeimeris generosa Gould 356 



4. — Glyeimeris generosa G ould 357 



5. — Glyeimeris generosa Gould 358 



6. — Glyeimeris generosa Gould 359 



7.— The Stearns tank 361 



8.— Screen for tank 361 



9.— Slatted platform for tank 361 



FRESH- WATER SPONGES. 



Fig. — 1. — Relative sizes and shapes of like parts of several sponges 391 



SEA SERPENT. 



Fig. 1.— Sea serpent. S. W. Hanna's sketch 408 



IX 



