BULLETIN 39, UNITED STATES NATIONAL MUSEUM. 



[72] 



A series of four points of different sizes for mounting insects is shown 

 in the accompanying illustration. The sharp-pointed one, a, is designed 

 for the minutest forms and the larger points for large insects. The 

 largest should be mounted on points of a nearly rectangular shape, shown 

 at d. The dimensions of these points as adopted by most entomologists, 

 are as follows : — 





Length. 



Breadth. 



Point. 



a 



6 



c 



d 



7. 5 mm. 

 7.5 

 7.5 

 7.5 



1. 5mm. 

 1.5 

 1.5 

 1.6 



.Omm. 

 .4 

 .6 

 1.6 



Fig. 99.— Insect mounted 

 on cardboard triangle. 



The point or triangle should be mounted on the pin and directed to the 

 left, the height from the top of the pin varying somewhat with the 

 specimen, but averaging about one-half an inch. 

 The insect is then glued to the point with the head 

 pointed forward. In the case of Coleoptera and 

 Hymenoptera, and in fact of most insects, the speci- 

 men is mounted with the back uppermost, but in the 

 case of the smaller Hymenoptera it is advisable to 

 mount some of the specimens, at least, on the left 

 side (see Fig. 99). This directs the legs toward the 

 pin, as a matter of safety, prevents their being 

 broken in handling, and also gives opportunity for 

 subsequent examination of the back, side, and venter 

 of the specimen. Ooleopterists always mount speci- 

 mens on the venter, and in the case of a correctly mounted specimen 

 the whole underside of the body should be available for examination 

 except the right half of the metasternum, as shown in figure 100. 



In mounting minute insects a few precautions are necessary. The 

 beginner usually uses too much glue or shell-lac, and the result is that 

 the mounted specimens are more or less covered with the fluid, so as to 

 render them unfit for examination. If, on the other 

 hand, too little of the glue is used, the specimens 

 are not securely fastened to the paper point, and 

 are liable to be jolted off by the slightest jar. Be- 

 fore mounting specimens the legs and antennse 

 must be brought into the proper position by means 

 of a brush or with a dissecting needle, so that 

 they may easily be seen. A supply of paper points 

 should always be at hand, and after selecting one 

 of the proper size for the specimen, with an acute 

 tip for a very small specimen and with a more obtuse point for a larger 

 one, a small quantity of glue is applied to the tip by means of a pointed 

 stick, such as a toothpick, the amount varying with the size of the 

 specimen. The tip of a moistened brush may be used to transfer the 



Fis. 100.— Method of gluing 

 beetle on paper point (ori- 

 ginal). 



