254 BULLETIN OF THE BUREAU OF FISHERIES. 



1.6; Cyclops, 0.7; cladocerans, 0.5; snails, 3.7; leech, 3; oligochEetes, 21.4; plants, 6.4; algae, 0.9; silt and 

 debris, 6.3. 



The food of the black bullhead, according to the summary, contains 45.1 per cent insects (larvae, 

 33.2; pupte, 4.2; adults, 5.7) and 21.4 per cent oligochsetes. Young fish apparently eat more oligo- 

 chsetes than adults. Forbes and Richardson (1908) examined 34 individuals of this species and found 

 the food to be one-fourth plants, and one-fifth bivave molluscs, snails, aquatic insects, crayfishes, and 

 other crustaceans. 

 Ameiurus nebulosus (Le Sueiu-). Common bullhead, brown bullhead, speckled bullhead. 



Station 5; May 21, 1915; number examined, 16. Length: Maximum, 94; minimum, 54.5; average, 

 64.7 Food: Unidentified insect larvae, i; Chironomus decorus larvae, 0.2; C. viridicollis larvae, i; C. 

 fulviventris larvae, 0.9; C. tentans larvae, 8.6; C. lobiferus larvae, 5.2; Helea larva, 0.3; Cricotopus trifascia- 

 tus larvae, 7.1; Ptychoptera larva, 1; May-fly nymphs, 0.6; Callibaetis nymphs, 0.7; beetle larva, 1.2; 

 carabid-beetle larva, 0.3; unidentified pupa, 0.3; Probezzia pupa, 0.6; unidentified insect fragments, 

 2.2; midges, o.i; mites, 1.2; Hyalella, o.6;ostracods, 21; Cyclops, 11; Chydorussphaericus, 22; Eurycercus 

 lamellatus, 2 ; Ceriodaphnia, o.i;cladoceranephippia, 0.7; snail, 0.5; plants, 2.3; sand and fine debris, 7.3. 



Summary. — Food: Insect larvEe, 28.1; insect pupae, 0.9; adult insects, 2.3; mites, 1.2; ostracods, 21; 

 Cyclops, 11; cladocerans, 24.8; snail, 0.5; plants, 2.3; silt and debris, 7.3. 



Station 6; June 24; number examined, i. Length: 86. Food: Palpomyia longipennis larvae, 10; 

 Callibaetis nymphs, 5; Caenis diminuta nymphs, 10; Enallagma hageni nymphs, 25; fragments of adult 

 insects, 50. 



Station 5; August 9; number examined, 33. Length: Maximum, 47.6; minimum, 25; average, 

 36.2. Food: Unidentified chironomid larvae and cases, 2.8; Chironomus fulviventris larvae, 5; C. lobi- 

 ferus larvae, 6.3; Protenthes culiciformis larvae, 7.3; Probezzia glaber larvae, 1.3; P. pallida larvae, 0.6; 

 Baetis nymphs, 2 ; Enallagma hageni nymphs, 1.3; insect pupae, 0.8; chironomid pupae, i; Chirono- 

 mus lobiferus pupa;, 6; adult midges, 2.3; Anax Junius, 0.2; gyrinid beetle, 0.5; Collembola, 0.5; 

 mites, o.i; Hyalella, 18; ostracods, 2; Cyclops, 6; Bosmina, o.i; Chydorus sphaericus, 9; Eurycercus, 

 0.3; Camptocercus, 17; Pleuroxus procurvatus, 4; Acroperus, 0.5; Ceriodaphnia, 1.6; Scapholeberis, 

 0.3; oligochsetes, 4.7. 



Summary.— VooA: Insect larvae, 26.6; insect pupae, 7.8; adult insects, 3.4; mites, 0.1; Hyalella, 

 18; ostracods, 2; Cyclops, 6; cladocerans, 32.3; oligochsetes, 4.7. 



Grand summary.— Number examined, 50. Length: Maximum, 94; minimum, 25; average, 46.3. 

 Food: Insect larvae, 28.2; dipterous pupae, 2.1; adult insects, 4.4; mites, 0.4; amphipods, 11. 4; ostra- 

 cods, 6.7; copepods, 8.4; cladocerans, 33.1; snails, 0.1; oligochaetes, 2.1; rotifers, +; protozoans,-!-; 

 plants, 0.9; alga?, +; silt and debris, 2.3. 



Of the food of this bullhead 42.1 per cent consists of microscopic Crustacea, 34.7 per cent of insects. 

 It apparently feeds more on Entomostraca than the black bullhead. Forbes and Richardson (1908) 

 found the food to consist chiefly of small bivalve molluscs, insect larvae, distillery slops, and a few adult 

 insects and snails. Hankinson (1908) states that this species is an omnivorous feeder, taking crayfish, 

 fish, molluscs, entomostracans, leeches, beetles, May-fly and dragon-fly nymphs. Tracy (1910) found 

 "all kinds of animal life," including the young and eggs of fishes. Reighard (1915) records small fishes 

 and a bumblebee as food. Crustaceans formed the chief food of the yoimg individuals examined by 

 Baker (1916), while the older fish had eaten 10 per cent Mollusca and 90 per cent vegetation and mud. 



The brown bullhead feeds mostly on Entomostraca and insect larvae while it is young, and when 

 mature takes almost anything in the shape of animal food. 

 Amiatus calva (Linnaeus). Bowfin", grindle. 



Station 17; August 24, 1915; number examined, i. Length: 545. Food: Crayfishes, 100. 



Station 28; September 14; number examined, 6. Length: Maximum, 438; minimum, 383; 

 average, 406. Food: Fish remains, 37.5; Lepomis incisor, 59.3; crayfish, 3. 



Station 28; September 17; number examined , 4. Length: Maximum, 543; minimum, 38S; average, 

 470. Food: Fish remains, 48.5; sunfish, 43.5; crayfish, 7.5. 



Station 22; July i, 1916; number examined, 3. Length: Maximum, 465; minimum, 440; average, 

 452.6. Food: Fish remains, 96.6; crayfish remains, 3.3. 



Summary. — Food: Fish remains, 96.6; crayfish remains, 3.3. 



a Locally known as dogfish. 



