268 BULLETIN OF THE BUREAU OF FISHERIES. 



Station 5; May 12; number examined, 8. Length: Maximum, 47.5; minimum, 28.6; average, 36.3. 

 Food: Chironomus larvae, 2.5; Camptocercus, o.i; Chydorus, 27.8; cladocerans, 1.2; plant remains, i; 

 filamentous algae, 49. 5; fine debris, 17.7. 



Summary.— Pood: Insect larvae, 2.5; cladocerans, 29.1; plants, i; algae, 49.5; debris, 17.7. 



Station 16; May 15; number examined, 6. Length: Maximum, 54; minimum, 26; average, 31.9. 

 Food: Insect eggs, 8; Orthocladius sordidellus larvae, 6.6; Chironoraus larvae, 14. i ; ostracods, 0.5; Cyclops, 

 II. 6; Canthocamptus, 20.5; Pleuroxus, +; Chydorus, o.i; oligochaetes, 29.1; Oscillaria, 3.^; desmids and 

 diatoms, 4.5. 



Summary. — Food: Insect larvae, 28.7; ostracods, 0.5; copepods, 32.1; cladocerans, o.i; oligochaetes, 

 29.1; algae, 7.8. 



Station si June i; niunber examined, i. Length: 47.5. Food: Chironomus larvae, 85; Cyclops, 

 9; chydorids, 6. 



Station s; June 24; number examined, g. Length: Maximum, 42.6; minimum, 32.2; averse, 

 36.2. Food: Orthocladius sordidellus larvae, 2.5; Tanytarsus dives larvae, 2.5; Chironomus larvae, 0.1; 

 C. tentans larvae, 10; Heptageniainterpunctata larvae, 6.1; Orthocladius sordidellus pupae, 21.5; Chirono- 

 mus pupae, II. i; Tanytarsus dives adults, 1.6; Hydroptilus imdulatus adults, 4.3; Stenelmis crenatus 

 adult, 2.6; ephippial eggs, 2.2; Wolffia, 14; sand, 21.5. 



Summary. — Food: Insect larvae, 21.2; pupae, 32.6; adult insects, 8.5; cladocerans, 2.2; plants, 14; 

 sand, 21.5. 



Station 19; July 3; number examined, 11. Length: Maximum, 45; minimum, 35; average, 39.9. 

 Food: Chironomus lobiferus larvae, 3.4; Cricotopus trifasciatus larvae, 4.5; adult insects, 1.3; mites, i; 

 Eurycercus, 5; Bosmina, i; Ceriodaphnia, 0.5; Daphnia longispina hyalina, 42.6; Daphnia, 5.4; Pleu- 

 roxus, 0.1; Chydorus, 13.5; chydorids, 1.4; Wolffia, 3.2; filamentous algae, 16.8. 



Summary. — Food: Insect larvae, 7.9; adult insects, 1.3; mites, i; cladocerans, 69.5; plants, 3.2; 

 algae, 16.8. 



Station 18; August 18; number examined, 8. Length: Maximum, 49; minimum, 24; average, 

 35.7. Food: Chironomus larvae, 0.6; Corethra adults, 6.3; Triaenodesflavescens adults, 5.6; sapromyzid 

 fly, 2; Ceriodaphnia, 25.5; Daphnia longispina hyalina, 58.8; Chydorus sphsericus, 1.2. 



Summary. — Food: Insect larvae, 0.6; adult insects, 13.9; cladocerans, 85.5. 



Station 18; August 21; number examined, 10. Length: Maximum, 30.5; minimum, 16.8; averse, 

 24.5. Food: Chironomus larvae, i; Corethra adults, 7; Chironomus tantans adults, 6; C. viridis adults, 

 25; Probezzia glaber adults, 6.2; chalcid fly, 4.3; Hyalella, 0.8; Cyclops, 8.5; Camptocercus, i; Bos- 

 mina, 5.5; Ceriodaphnia, 27; Daphnia longispina hyalina, 3; ephippial eggs, 3.5; Hydrodictyon, 1.2. 



Summary. — Food: Insect larvae, i; adult insects, 48.5; amphipods, 0.8; copepods, 8.5; cladocerans, 

 39; algae, 1.2. 



Station 17; August 23; number examined, 10. Length: Maximum, 33; minimum, ig.8; average, 

 24.5. Food: Probezzia larvap, 2.5; Chironomus lobiferus larvae, 33. 3; pamid larvae, 0.3; hemipterous 

 nymph, i; Chironomus pupae, 2; Tanytarsus dives adults, i; mites, 2.4; ostracods, 0.5; Cyclops, 7.8; 

 Canthocamptus, 0.5; Acroperus, 0.2; Camptocercus, 0.4; Bosmina, 0.5; Simocephalus, 41.2; Chydorus, 

 3.9; oligochaetes, 2. 



Summary. — Food: Insect larvae, 36.1; pupae, 1.2; adult insects, i; mites, 2.4; ostracods, 0.5; cope- 

 pods, 8.3; cladocerans, 46.2; oligochaetes, 2. 



Grand summary. — Number examined, 80. Length: Maximum, 54; minimum, 16.8; average, 34. 

 Food: Insect eggs, 0.7; insect larvae, 12.8; pupae, 4; adult insects, 9.2; mites, 0.5; amphipods, 0.1; ostra- 

 cods, 0.5; copepods, 11; cladocerans, 33.4; oligochaetes, 2.1; rotifers, 2.2; plants, 3.9; alga;, 11. 7; debris, 

 4.1; sand, 2.4. 



The food of this minnow consists for the most part of entomostracans (44.9 per cent), aquatic plants 

 and algae (15.6 per cent), and insects (26.7 per cent). The sparcity of ostracods and oligochaetes indi- 

 cates tliat it does not feed on the bottom . The abundance of Canthocamptus, chydordis, algae , and rotifers 

 make it probable that the food is secured among aquatic vegetation. Forbes and Richardson (1908) 

 found the food to be mostly entomostracans, also insect larvae, amphipods, flowers, seeds, and algae. 

 Hankinson (1908) reported adult midges, algae, and a few entomostracans. 



