6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. IO3 



separation, the water alone, at first, falling to the bottom. Of the 

 three last named, diethyl carbonate is the most efficient solvent. It is 

 less volatile than ether and therefore safer to handle. 



III. STEPS PREPARATORY TO MOUNTING 



When thoroughly degreased and ready for mounting, specimens 

 should be removed from the ether bath to a pad of absorbent tissue, 

 where, if desired, jaws may be separated and genital extrusions com- 

 pleted. Carabid jaws may best be opened by springing them apart 

 by means of fine forceps applied ventrally. Provided the killing tech- 

 nique has been followed as indicated, the jaws will yield readily and 

 the disclosed mouth parts may then be easily cleaned with a soft 

 camel's-hair brush dipped in ether. Partial extrusion of the genital 

 apparatus of males may be successfully completed by slight pressure 

 on the abdomen ; should this not produce the desired result, the insect 

 is placed ventral surface uppermost and held while a sharp needle is 

 inserted in a membranous portion of the median lobe and the latter 

 gently extracted. The laterally curved aedeagi of carabids require 

 urging counterclockwise in the direction of their curvature. Any 

 fluids escaping from the body during the process of handling should 

 be washed off in a bath of clean ether. If the specimen is minute, 

 the operation should be performed in fluid (ether or Barber's fluid) 

 under a binocular, a special tool of fine pin wire or drawn glass hold- 

 ing the beetle firmly against the bottom of the dissecting dish (fig. i). 



It is desirable to transfer drying specimens to a smooth, clean sur- 

 face (preferably glass) for the final arrangement of their appendages. 

 In preparation for the slip method of mounting, the legs are oriented 

 close to and on a plane with the body, and the antennae are directed 

 backward along the sides. Until cleared mounts of genitalia are de- 

 sired, these organs had best be left attached to the abdomen ; in 

 male Carabidae and Cicindelidae, they tend to orient pointing clock- 

 wise as seen from above and in this position they are most convenient 

 for study. 



IV. MOUNTING ON TRANSPARENT SLIPS 



A sufficient series of each species collected at one time and under 

 the same ecological conditions are assembled and are ready for 

 mounting as soon as their surfaces are dry. Mounting should be 

 done before the insects have become stiff, since the legs in drying 

 tend to elevate the body slightly and this necessitates relaxing the 

 specimens again before they can be properly cemented to a plane 



