I 



NO. 6 PREPARATION OF COLEOPTERA VALENTINE I5 



hesive employed should be acetate cement, somewhat diluted with 

 ethyl acetate. Each lot, representing a day's catch or an ecological 

 aggregate, is circumscribed with an ink line and labeled with the 

 date and locality, or with the date plus some symbol referring to a 

 category in the chronologically arranged notes. The boxes are stored 

 chronologically in cardboard filing cases (12 by 6J by 5 inches), 

 where they stand vertically, hinge uppermost, each bearing an adhe- 

 sive-tape label along its upper edge. If the cementing has been care- 

 fully done and the specimens are clean, the chances of their breaking 

 loose, even in shipping, are extremely remote. Space for naphthalene 

 on the bottom of the filing case is provided by the recess in which 

 the filing mechanism operates. However, should dermestids succeed 

 in entering the tin boxes, they can be destroyed without disturbing 

 the contents simply by dousing specimens and all with carbon tetra- 

 chloride and shutting the lids for a few hours. 



The chief advantages gained by the above technique lie in the 

 visibility of the specimens and in the compactness of their arrange- 

 ment. If at any time a beetle is required for mounting, it may be 

 detached immediately from the cardboard after an application, by 

 brush or pipette, of ethyl acetate. It should then be immersed in the 

 relaxing bath (XI) where any residual cement will be dissolved. 



b. Preservation in fluid. — Adequate preservation of soft parts with 

 minimum hardening of tissues and stififening of joints are the criteria 

 for a good entomological preservative. In the writer's opinion. Bar- 

 ber's relaxing mixture (XI) meets these requirements better than 

 ! any preservative in common use. Ethyl acetate-killed material, stored 

 jin this fluid either before or after ether treatment, has emerged years 

 later in an excellent state of preservation and perfectly relaxed. It 

 has proved particularly useful as a preservative or softener for 

 j carabid beetles captured in molasses traps, the specimens being soaked 

 I in the fluid after having been thoroughly washed and partly dried. 

 In using Barber's fluid as a preservative over a long period of time, 

 it is important to remember to change the supply as often as it be- 

 comes darkened by dissolved oils. When the bulk of material is great, 

 several changes may be required. 



Because of their hardening properties, neither alcohol nor formalin 

 should be employed alone as a preservative when flexibility of articu- 

 lations is prerequisite to the mounting technique adopted. Further- 

 more, the use of these fluids in killing and preserving seems to in- 

 hibit, somewhat, the action of degreasing agents. However, the ease 

 with which specimens can be collected and preserved in alcohol fre- 

 quently justifies its use, especially when time, simplicity of method. 



