FOOD OP THE SHORE FISHES OF CERTAIN WISCONSIN LAKES. 253 



Station 18; August 18; number examined, i. Length: 59. Food: Chironomus viridis larvae, 20; 

 Baetisca nymphs, 20; Chironomus lobiferus pupse, 60. 



Station 23; August 19; number examined, i. Length: 22.5. Food: Chironomus lobiferus larvae, 73; 

 Cyclops, 10; oligochsetes, 15. 



Station 10; August 20; number examined, 2. Lengths: 31.5, 29. Food: Labidesthes sicculus, 45; 

 Chironomus lobiferus larvae, 2.5; Chironomus digitatus larvae, 12.5; Baetisca nymphs, 40. 



Station 23; September 21; number examined, i. Length: 109. Food: oligochaetes, 50; plant 

 remains, 20; sand and mud, 30. 



Station 15; September 25; number examined, i. Length: 112. Food: Cambarus propinquus, 100. 



Station 15; November 20; number examined, 2. Lengths: 160, 121. Food: Labidesthes sicculus, 

 42.5; Bastis nymphs, 2.5; Sialis infumata larva, 50; Chironomus lobiferus pupae, 5. 



Station 25; December 4; number examined, i. Length: 230. Food: Crayfish, 100. 



Grand summary for igi4 and igiS- — Number examined, 45. Length: Maximum, 230; minimum, 

 22.5; average, 72.9. Food: Fish, 2; dipterous larvae, 19. i; May-fly nymphs, 3.5; Odonata nymphs, 14.4; 

 caddis-fly larvae, 2.8; Sialis infumata larvae, 2.2; beetle larvs, 0.5; unidentified insect larvae, 0.5; dipter- 

 ous pupae, 9.6; Diptera, 4.8; Hemiptera, 1.2; Hymenoptera, 1.3; Coleoptera, i.i; unidentified insects, 

 5.3; hydrachnids, 0.2; crayfish, 16. i; amphipods, 1.4; ostracods, 0.3; copepods, 0.3; cladocerans, 4.3; 

 gastropods, -f ; oligochaetes, 3; plant remains, 2.8; algae, 0.5; silt and dftris, 1.2. 



The summaries show that the food of the young rock bass consists largely of insects (larvs, 43 per 

 cent; pupae, 9.6 per cent; adults, 13.7 per cent), which constitute more than three-fourths of the food. 

 The adult fish feed mostly on crayfish, though they also capture insects in considerable numbers. 

 Forbes and Richardson (1908) state that this bass eats insects, small crustaceans, and a few fish. Han- 

 kinson (1908) found that it fed chiefly on crayfish, with smaller percentages of dragon-fly nymphs, midge 

 larvae, small fishes, and May-fly nymphs. Reighard (1915) found fish, insects, and crayfish in those he 

 examined. According to Baker (1916) about three-quarters of the food is Crustacea and the remainder 

 plants, algae, insects, and debris. 



Ameiurus melas (Rafinesque). Black bullhead. 



Dalafor 1^14 (Pearse, 1915). — Number examined, 2. Length: Maximum, 123; minimum, 38.2; 

 average, 80.6. Food: Dipterous larvae, 40; Diptera, 2.5; ostracods, 12; Cyclops, 2.5; unidentified clado- 

 cerans, i; Bosmina, 25; plant remains, 17.5. 



Station 5; August 18, 1915; number examined, i. Length: 274. Food: Enallagma hageni nymphs, 

 2; Gyrinus larva, 6; dytiscid larva, 2; Leptocerus larva, 3; Phryganea interrupta larva, 5; caterpillar, 20; 

 Chironomus fulviventris pupa, 16; Chironmus fulviventris adult, 11; Enallagma hageni adult, 13, 

 Psychoda adult, i; Corixa adult, 10; crayfish claw, i; Hyalella, i; leech, $; Lemna, 3. 



Summary. — Food: Insect larvae, 38; insect pupae, 16; adult insects, 35; crayfish, i; Hyalella, i; 

 leech, 5; Lemna, 3. 



Station 5; September 14; number examined, i. Length: 275. Food: Chironomus decorus larvae, 

 30; C. lobiferus larvae, 20; C. digitatus larvae, 5; Enallagma hageni nymphs, 5; Chironomus decorus 

 pupa, 30; C. lobiferus pupa, 8; Hyalella, 2. 



Summary. — Food: Dipterous larvae, 60; dipterous pupae, 38; Hyalella, 2. 



Station 28; September 17; number examined, i. Length: 280. Food: Probezzia glaber larvae, 4; 

 P. pallida larvae, 4; Tipula abdominalis larva, i; Planorbis, 25; Physa, 30; plants, 10; Lemna, i; Nostoc, 

 15; silt and dftris, 10. 



Summary. — Food: Dipterous larvae, 9; snails, 55; plants, 26; silt and debris, 10. 



Station 16; September 20; number examined, 10. Length: Maximum, 190; minimum, 33; average, 

 79.3. Food: Chironomus decorus larvae, 6.3; C. fulviventris larvae, 10; C. tentans larvae, 0.5; Chironomus 

 sp. larvae, 11.5; Protenthes culiciformis larva, o.i; Probezzia glaber larvae, 1.6; P. pallida larva, 4.5; 

 Chironomus decorus pupa, 0.6; C. fulviventris adults, 5.4; crayfish, 9.2; Cyclops, 0.5; leech, 4; oligo- 

 chaetes, 32.1; plants, 4.7; silt and fine debris, 8.5. 



Summary. — Food: Chironomid larvae, 24.5; chironomid pupae, 0.6; chironomid adults, 3.4; crayfish, 

 9.2; Cyclops, 0.5; leech, 4; oligochaetes, 32.1; plants, 4.7; silt and debris, 8.3. 



Grand summary for igi4 and 1915. — Number examined, 13. Length: Maximum, 280; minimum, 

 33; average, 118. 8. Food: Dipterous larvae, 32.6; damsel-fly nymphs, 0.4; beetle larvae, 0.4; caddis-fly 

 larvae, 0.5; caterpillar, 1.3; dipterous pupae, 4.2; adult insects, 3.7; Hyalella, 0.2; crayfish, 6.1; ostracods, 

 69571°— 18 17 



