. Bulletin - United States National Museum. Science. 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. 1. 5mm. .Omm. .4 .6 Fig. 99.—Insect mounted on cardboa
. Bulletin - United States National Museum. Science. 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. 1. 5mm. .Omm. .4 .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 sp
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Keywords: ., bookauthorun, bookcentury1800, bookdecade1870, booksubjectscience
