l68 Notes on Insectworous Coleoptera. 



more or less prominent angle at about the anterior third of 

 the outer margin, although this margin is sometimes reg- 

 ularly curved. In two genera, Agonoderus and Stenolo- 

 phus, this plate is produced forward and outward beyond 

 the articulation with the palpus (which thus seems to 

 spring from beneath it), forming an oblique lamina with a 

 rounded outer angle and an acute tip. This character 

 seems to distinguish Stenolophus from Harpalus, as far as 

 I have been able to compare the species. 



Food of the Carabid^. 



The large numbers of Carabidae eaten by several of our 

 common birds make it important that the somewhat doubt- 

 ful food habits of this family should be more thoroughly 

 studied ; and I have undertaken the microscopic examina- 

 tion of the contents of stomachs and intestines as one 

 branch of this investigation. The facts thus obtainable 

 perhaps cannot give us a complete idea of the food of these 

 insects, but should probably be taken in connection with 

 field observations, as these beetles are said frequently only 

 to suck the juices of their prey, rejecting the solid parts; 

 and where this has been done the fact will be only obscure- 

 ly indicated by the contents of the alimentary canal. 

 Where this contained an abundance of fatty chyme with 

 no solid tissues to fix its source, I have sometimes doubt- 

 fully inferred such an event ; but usually liquid food will 

 escape detection. 



The results of the examinations thus far made are so in- 

 teresting that I am impelled to give the method I have 

 found most successful and convenient, with the hope that 

 others may turn their attention to the same subject. The 

 dissection should be made as soon as possible after the 

 beetle is taken, — within a few days at farthest, — as the 

 more unstable elements of the food are apparently soon 

 changed, even in strong alcohol. If the beetle is as large 

 as Megilla maculata, the elytra and wings may be cut off 

 and then, while the insect is held between the thumb and 

 finger of the left hand, the edges of the abdomen may be 

 carefully trimmed away with a pair of fine scissors (those 

 with curved blades are best) leaving the soft dorsal cover- 



