NO. 7 



PROTECTIVE ADAPTATIONS McATEE 



19 



that in natural history as elsewhere sweeping statements hased on 

 partial or negative evidence are dangerous. N(j exception may be 

 noted for one which claims that " enemies play no part in keeping 

 down the numbers of Artcmia (brine shrimps), or of Epiiydra 

 (alkali flies) in the larval stage." ' Dr. Alexander Wetmore, of the 

 Smithsonian Institution, who has had considerable experience about 

 Great Salt Lake to which locality the quoted assertion relates, has 

 pointed out ' that Arlcmia and Ephydra are by no means free from 

 enemies. Shovellers, lesser scaups, golden-eyes, green-winged teal, 

 Wilson's and northern phalaropes, avocets, and black-necked stilts all 

 feed extensively upon both of these animals. But for the fact that 



Idoitificatioiis of Crustacea 



Number of 

 Group identifications 



Unidentified 573 



Anostraca 28 



Cladocera 90 



Ostracoda 207 



Copepoda 13 



Cirripedia 401 



Isopoda 385 



Amphipoda 986 



Cumacea 



Stomatopoda 



Schizopoda 48 



Decapoda 3355 



Stomach analyses have not been made of other birds collected at the 

 same place, it would undoubtedly be possible to add the names of 

 a number of species to this list. Doctor Wetmore states that " the 

 toll taken by birds from the brine shrimp and alkali fly larvae and 

 pupae during the course of a season constitutes a mass of individuals 

 almost beyond comprehension .... The immense numbers of these 

 creatures .... must be attributed to the large number of offspring 

 produced rather than to an absence of enemies." The number ol 

 records for the minute Cladocera is fully up to expectations. Among 

 other items of this group the ^gg capsules or ephippia of Daphnia 

 have been found in numerous stomachs of grebes and wild ducks, and 

 in number up to 250 in a single stomach. 



^Vorhies, Charles T., Notes on the fauna of Great Salt Lake. Amer. Nat., 

 vol. 51, pp. 494-499, Aug., 1917. 

 "Amer, Nat., vol. 51, pp. 753-755, Dec, 1917. 



