272 BULLETIN OF THE BUREAU OF FISHERIES. 



comuta, loo; oligochaetes, 98; filamentous algae, 90; silt and debris, 100. These figxires show that the 

 minnow is a versatile feeder. The food in the stomach has always been chewed into fine pieces. 



Forbes and Richardson (1908) stated that the stomach of this species is commonly packed with mud 

 containing filamentous algae and miscellaneous vegetable d6bris. Hankinson (1908) found the food 

 varies greatly, but consists chiefly of small organisms taken from the bottom, from water plants, and 

 from the water. These fish eat tlie eggs of the black bass, Johnny darter, miller's thumb, and sunfish. 

 Sometimes tliey devour the newly hatched fry of their own species. Other foods mentioned consisted 

 of filamentous algae, desmids, entomostracans, and insects. Reighard (1915) said tiiis minnow is a 

 "mud eater." 



Pimephales promelas (Rafinesque.) Black-head minnow, fathead. 



Station 17; September 18, 1915; number examined, 3. Lengths: 51, 50.5, 45. Food: Tanytarsus 

 gregarius larvae, 79.3; mites, 1.6; amphipods, 0.3; Cyclops, 2.6; oligochaetes, 6; diatoms and other algae, 

 1.3; sand and debris, 8.3. 



Pomoxis sparoides (Lac^pfede). Black crappie, calico bass, silver bass. 



Station 17; April 10 and 13, 1915; number examined, 4. Lengths: 145,130,132,75. Food:Miimows, 

 12.5; chironomid larvae, 1.2; May-fly nymphs, 22.5; Siphlurus nymphs, 0.7; Enallagma h^eni, 12.5; 

 Smithiurus, 0.5; Corixa adults, 24.5; Hyalella, 8.7; Chydorus sphaericus, 0.2; plant remains, 11.5; fil- 

 amentous algae, 2.3; fine debris, 1.2. 



Smnmary. — Food: Fish, 12.5; insect larvae, 36.9; adult insects, 25; amphipods, 8.7; cladocerans, 

 0.2; plants, II. 5; algae, 2.3; debris, 1.2. 



Station 21, along south shore of Lake Wingra; number examined, 4. Lengths: 154, 140, 70, 55. Food: 

 Fish, 6.2; Chironomus nigricans larvae, o.i; Tanypus monilis larvae, +; Probezzia larvae, 10; caterpillar, 

 11; Baetis nymphs, 4.5; Chironomus fulviventris pupae, 38.5; mites, 1.3; Dikerogammarus fasciatus, 

 0.5; Hyalella, 10; ostracods, 2.5; Cyclops bicuspidatus, 21. i; Chydorus sphaericus, 1.8; filamentous 

 algae -f-- 



Summary. — Food: Fish, 6.2; insect larvae, 24.3; pupae, 38.5; mites, 1.3: amphipods, 10.5; ostracods, 

 2.5; copepods, 21.1; cladocerans, 1.8; algae, 4-. 



Station 17; August 24; number examined, i. Length: 186. Food: Caenis diminuta nymph, 8; 

 moth, 81; Eurycercus lamellatus, i; Wolffia, 10. 



Station 6; August 25; number examined, i. Length: 100. Food: Chironomus viridis larvae, 10; 

 C. lobiferus pupae, 10; Hyalella, 15; Simocephalus, 61.9; Ceratophyllum, 3; seed, o.i. 



Station 28; September 15; number examined, 3. Lengths: n6, 105, 104. Food: Fish, 79; Chiron- 

 omus viridis larvae, 0.3; Caenis diminuta nymph, i; Corixa adult, 3.3; Cyclops, 0.3; Chydorus, 0.2; 

 Daphnia, 11. 7; plant remains, 3.3. 



Station 24; September 17; number examined, i. Length: 45. Food: Insect larvae, 15; chironomid 

 larvae, 10; Hyalella, 60; Cyclops, 3; Chydorus sphaericus, 2; Daphnia, 10. 



Station 22; October 27; number examined, 36. Length: Maximum, 48; mininum, 36; average, 40.4. 

 Food: Fish, 0.3; insect larvae, i; chironomid larvae, 3.6; Tanypus gregarius larvae, 9; Baetisca nymph, 

 4.3; Chironomus lobiferus pupae, 0.4; Smithimois, 0.6; moth, 0.4; adult midges, 2.5; Probezzia pallida 

 adults, 5.8; Cordylura adults, 0.6; Hyalella, 3.5; ostracods, 21.7; Diaptomus, 0.2; Canthocamptus, 20.7; 

 Cyclops, 18.6; Chydorus, 1.5; Pleuroxus, i; Simocephalus, +; seeds, 0.4. 



Summary. — Food: Fish, 0.3; insect larvae, 17.9; pupae, 0.4; adult insects, 9.9; amphipods, 3.5; ostra- 

 cods, 21.7; copepods, 29.5; cladocerans, 1.5; plants, 0.4. 



Station 26; November 27; number examined, 7. Length: Maximum, 221; minimum, 160; average, 

 184. 1. Food: Insect larvae, 0.8; Chironomus viridis larva;, 8.9; C. tentans larvae, 4.3; Baetisca nj'mphs, 

 2.1; Isclinura verticalis nymphs, 2.1; Canthocamptus, +; Daphnia, 54.7; Leptodora, 27.1. 



Summary. — Food: Insect larvae, 18.2; copepods, +; cladocerans, 81.8. 



Station 18; April 29, 1916; number examined, 3. Length: Maximum, 188; minimum, 159: average, 

 172.3. Food: Minnow, 13.3; Chironomus fulviventris larvae, 3.3: C. lobiferus larvae, 3.^; Ephemerella 

 sp. nymphs, 1.6; Celithemis eponina nymph, 6.6; Sctodis grandis larvae, 0.3; Corixa adult, 1.6; Hyalella, 

 69; filamentous algae, 0.3; leaf 0.1; plant remains, 0.1. 



Summary. — Food: Fish, 13.3; insect larvae, 13.1; insect adults, 1.6; amphipods, 69; plants, 0.5. 



