14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. IO3 



by placing them (after dehydration in strong alcohol and clearing 

 in xylol) in small sections of glass tubing drawn to an appropriate 

 gauge and filled with balsam or, better still, with a color-stable gum 

 damar. One end of the tube is left open for addition of more mount- 

 ing medium as contraction takes place ; the other end is closed with 

 a tiny cork plug, or by embedding it in a small cork block in which 

 a suitable recess has been cut with a cork borer. Through the free 

 end of the cork is thrust the pin of the specimen which yielded the 

 dissection. The tube should eventually be sealed with thick acetate 

 cement. Examination of its contents should be made in xylol or 

 cedar oil, where virtually all optical interference due to the curved 

 glass will be eliminated. 



The presence of small air pockets trapped within or adjacent to a 

 dissection in a freshly made balsam mount need not be viewed with 

 concern; after a few hours, these will disappear. 



IX. MOUNTING LARVAE 



Soft-bodied forms, especially the larvae of Coleoptera, have been 

 successfully treated exactly as the adults and mounted with them 

 on the same slips. There is but one departure in technique : While 

 drying, after having been thoroughly soaked in ether, the specimen 

 is warmed under an electric lamp sufficiently to cause expansion of 

 the gas within its body and consequent distention. The heat must 

 be carefully applied and maintained for a few minutes until the speci- 

 men has dried in an inflated condition. Too sudden an increase in 

 heat will cause rupture, too gentle an application will cause collapse 

 of the body.^ 



X. CARE OF ACCESSORY MATERIAL 



a. Dry stoi-age. — The flat tin boxes in which 50 cigarettes are 

 sold provide admirable storage facilities for Coleoptera. They may 

 be made to do double duty if both top and bottom are utilized. After 

 the metal is first scored with a sharp instrument, two pieces of heavy, 

 smooth cardboard are attached, one to each of the inner surfaces, 

 by means of a suitable cement (such as "Metallic X"). To these 

 cards the ethyl acetate-killed, ether-treated specimens are cemented 

 in close array, with legs at the sides and antennae pointing backward. 

 This should be done while the beetles are still relaxed, and the ad- 



° This method has yielded excellent results in the preparation of degreased 

 and dehydrated lepidopterous larvae of both smooth and hairy species. 



