8 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. IO3 



that they may be cut apart without danger to appendages ; and an 

 ample margin of free sheeting should remain in back of each group 

 in order that the pin, which is placed there, may not interfere with 

 hand-lens observations of the specimens nearest it (fig. 3). Standard 

 Strips of 15-gauge sheeting cut in ^- and |-inch ( 13-mm. and lo-mm.) 

 widths w^ill greatly facilitate the mounting of small to minute speci- 

 mens and will lend a neat appearance to the collection. The beetles 

 should face and be close to a long edge ; the slips bearing series or 

 single specimens can then be speedily cut apart in one operation yield- 

 ing mounts of uniform dimension from back to front with the speci- 

 mens thereon occupying similar relative positions. If sufficiently 

 heavy sheeting is used for large beetles, it is seldom necessary to 



SGtFans.T^irUCa.V, 

 IX ; '33 'i50' 

 J.M VQ.lentlne 



Fig. 3 



Fio-. 4 



Fig. 3. — The cellulose acetate slip method of mounting in series. 

 Fig. 4. — The cover glass slip method of mounting in series. 



place the pin in any position other than the standard one, in the 

 center of the rear of the mount. Should, however, an extra large 

 mount require reinforcement, a drop of cement placed at the point 

 of exit of the pin will suffice. 



A good-quality, clear cement of cellulose base * should be used. It 

 should not be applied straight from the container, however, but 

 should first be diluted with sufficient solvent to allow small drops to 

 form slowly on the head of a pin after the mixture has been thor- 

 oughly stirred. At least two lots should be made up, one diluted 

 with ethyl acetate and the other with amyl acetate. The former is 

 relatively quick-drying and is used in cementing firmly all but the 

 smallest specimens to their acetate mounts ; the latter is slower to 

 dry and therefore more useful in attaching minute specimens and 

 in mending broken appendages. A convenient applicator is the 

 head of a long, fine insect pin stuck into the cork of the vial in which 



* Duco "household" cement has been found very serviceable. 



