36 BULLETIN 862, U. S. DEPARTMENT OF AGRICULTURE. 



crab (Hccapanopeus angustifrons) wnich frequents the beaches there. 

 One gizzard contained the claws and other remains of at least 30 of 

 these crabs. When crawfish are eaten by ducks, small plano- 

 convex masses of calcareous matter known as gastroliths, supposed 

 to be used as material for a new exoskeleton after moulting, often 

 are found, with the fingers or claws persisting in the stomach after 

 other parts of the crawfish are digested. Small bivalved crustaceans 

 (Ostracoda) had been taken by 38 of the pintails, sand fleas or beach 

 fleas (Amphipoda) by 20, and sowbugs (Isopoda) by 5. 



INSECTS (iNSECTA), 2.85 PER CENT. 



Beetles (Coleoptera) amounting to 0.93 per cent of the total food 

 of the pintail, consisted largely of three families, the predacious 

 diving beetles (Dytiscidae), water scavenger beetles (Hydrophihdae), 

 and ground beetles (Carabidae). Others represented were the snout 

 beetles (Curculionidae) , leaf beetles - (Chrysomelidae), leaf chafers 

 (Scarabaeidae), crawling water beetles (Haliplidae), rove beetles 

 (Staphylinidae) , click beetles (Elateridae), flat bark beetles (Cucuji- 

 dae), and tiger beetles (Cicindelidae) . Besides these there were the 

 fragments of many unidentified beetles and the larvae of aquatic 

 species. 



Flies (Diptera) found in the pintail stomachs consisted mainly 

 of larvae and amounted to 0.85» per cent of the total food. The 

 following families of flies were represented : Midges (Chironomidae), 

 in 31; brinefhes (Ephydridae), in 15; soldierflies (Stratiomyidae), 

 in 8; craneflies (Tipulidae), in 3; horseflies (Tabanidae), in 2; and 

 unidentified fly remains in 10 stomachs. 



The larvae or nymphs, and a few adults, of dragonflies (Anisoptera) 

 and damselflies (Zygoptera), together furnished 0.44 per cent of the 

 pintails' food; bugs (Heteroptera), consisting chiefly of water boat- 

 men (Corixidae), creeping water bugs (Naucoridae) , and giant water 

 bugs (Belostomatidae), amounted to 0.23 per cent; the larvae and 

 larval cases of caddisflies (Phryganoidea), 0.2 per cent; and other 

 insects, consisting of a few grasshoppers (Orthoptera), ants and 

 wasps (Hymenoptera), and Mayflies (Agnatha), totaled 0.2 per cent. 



MISCELLANEOUS ANIMAL FOOD, 0.4 PER CENT. 



The remains of small fish (found in 16 stomachs), a frog (Rana sp.), 

 mandibles of a few marine worms {Nereis sp.), tiny water mites 

 (Hydrachnidae), bits of hydroids (Hydrozoa), corallines (Bryozoa 

 and Alcyonaria), and the minute, lime-incrusted, one-celled organ- 

 isms known as Foraminifera, all were included in the varied bill of 

 fare of the pintail. 



