102 PROCEEDINGS OF THE NATIONAL MUSEUM vOL. 106 



Trapped mammals were examined immediately for ants, which 

 were removed. All specimens except fur bearers were then 

 placed in No. 3 or No. 5 paper bags. The mouth of the bag was 

 closed by twisting the paper tightly. Specimens were separated 

 as to locality and species during the winter months. Usually, in 

 late spring, summer, and fall each specimen was placed in a 

 separate bag. Fur bearers were placed in burlap or cloth bags or 

 were taken to the laboratory uncovered. 



In the laboratory the paper bags and the specimens were ex- 

 amined for chiggers. The bags were torn open, smoothed out, 

 and inspected with hand lens or dissecting microscope. The mam- 

 mals were examined with the aid of the hand lens or the dis- 

 secting microscope, with particular attention being given to the 

 ears in all species and to the posterior portion of the venter and 

 the rump on shrews. Chiggers often were found crawling on 

 the fur. 



Some chiggers were removed directly from their places of 

 attachment by use of a dissecting needle, but it was preferred 

 to permit them to free themselves. At the beginning of the 

 second winter's trapping, it became standard routine first to 

 examine the hosts visually and to remove chiggers already de- 

 tached. Hosts not preserved and freshly prepared study skins 

 were then placed on wire screens in funnels over water. This was 

 an adaptation of the Berlese funnel. A low rack was made which 

 held seven funnels. Glass and metal funnels of standard shape 

 and funnels with straight sides were used. These funnels were 20 

 to 24 cm. in diameter. Screens of hardware cloth were cut to fit 

 about 2.5 cm. inside the funnels. Beakers, finger bowls, and the 

 bottoms of weighing bottles half filled with water were placed 

 under the funnels to receive the chiggers when they detached. 

 To prevent migration of chiggers between funnels and between 

 collecting dishes, benzol benzoate was applied to the rack between 

 the funnels and to squares of insulation board on which the col- 

 lecting dishes were placed. A bent dissecting needle was used to 

 pick up chiggers. To be effective in removing chiggers from fur 

 or paper, the tip of the needle was moistened with water. 



Chiggers which were to be used alive, if not immediately, were 

 placed in special vials (Farrell and Wharton, 1948) made by lin- 

 ing 25 X 15 mm. shell vials with a mixture of plaster of Paris 90 

 parts by weight and activated charcoal 10 parts by weight. 

 Stoppers were smooth No. 4 corks. The lining was kept moist 

 with distilled water. Chiggers to be preserved were mounted 



