436 University of California Publications in Zoology [VOL. 11 



langidae), the commonest of those found in pastures. In no 

 instance have more than two spiders been taken from the same 

 stomach. 



Economic importance. Spiders should be considered as doubt- 

 fully beneficial or of neutral value to the agriculturist, in spite 

 of the fact that they feed largely on insects. As a rule spiders 

 are not abundant enough to be of great economic importance. 

 Their destruction at the hands of the meadowlark is of no conse- 

 quence, as the resulting effect on insect life is so small. 



Miscellaneous Animal Food 



Miscellaneous articles of diet form three and one-half per 

 cent of the food for the year. The common sow-bug (Porcellio 

 scaber) is the commonest crustacean found in stomachs. Two 

 birds had eaten snails. Two birds from San Diego had each 

 taken a scorpion. But few earthworms have been found in the 

 stomachs. Centipedes (Scolopendra sp.) and millipedes (Julus) 

 appear to form a constant part of the diet. They are evidently 

 taken regularly where available. Two birds had eaten ant-lions 

 (Myrmeleon sp.). 



Quantity destroyed. Centipedes, millipedes, scorpions, ant- 

 lions, and sow-bugs may be considered oddities in the diet. Their 

 slight availability may account in some measure for the small 

 numbers taken by the western meadowlark. 



Economic importance. Of these miscellaneous elements in the 

 diet, only millipedes and sow-bugs can be considered injurious. 

 Centipedes are usually considered beneficial, scorpions injurious, 

 and ant-lions of neutral value. None of these forms is taken 

 in sufficient quantity to make their destruction either an injury 

 or a benefit. 



Inorganic Matter 



Pebbles, used for grinding the food, make up the inorganic 

 matter found in the stomachs. White and red pebbles, probably 

 because of their conspicuousness, predominate. Pebbles appear 

 to be necessary as an aid to the digestion of grain, but much less 

 necessary for the digestion of insects. Pebbles are nearly always 



