46 THE NORTH AMERICAN SPECIES OF DROSOPHILA. 



"messy" ones (grasshoppers, large Hemiptera, etc.) in the same con- 

 tainers. I ordinarily use glass vials for containers, and manipulate 

 the collections between two vials until all undesirables are eliminated. 

 When the collection is in the laboratory it is etherized, and one can 

 examine it carefully at leisure, and dispose of the specimens as he 

 wishes. 



If the specimens are to be preserved for taxonomic purposes they 

 should be "pinned" — not preserved in alcohol or other fluid. It is 

 not so convenient to examine them in a fluid; and descriptions are 

 made from dried material, so that the size, color, shape, etc., can be 

 more easily compared with descriptions and type specimens if the 

 material is dried. Most entomologists insist that Diptera should 

 always be actually pinned — never gummed on cardboard "points." 

 In practice, however, the small forms, like Drosophilinse, are usually 

 mounted on points; and the writer personally much prefers this 

 method. It is out of the question to stick a regular insect pin through 

 such small flies, after the fashion adopted for butterflies or other large 

 insects, for the thorax is thereby mutilated beyond recognition. One 

 is usually recommended to use "minuten-nadeln," which are very 

 minute pins, that must be fastened in some way to the regular pin. 

 This method is tedious, and leaves the specimen either insecurely 

 fastened, or else (if the small pins are stuck clear through the thorax) 

 somewhat mutilated. It is also difficult to carry out successfully on a 

 large scale when working with material that has been long dead and 

 dried, for even when relaxed such material is somewhat brittle. 



I now mount all my small Diptera on points. Narrow triangular 

 bits of cardboard (ordinary library cards are about the right thickness) 

 are cut, about 8 mm. long and just wide enough at the base to allow 

 an insect pin to be stuck through them. These are mounted, singly, 

 on rather stout insect pins, being placed about a third of the way from 

 the heads of the pins. The specimen is then fastened to the apex of the 

 triangle with a small drop of shellac or glue. The specimen should be 

 mounted on its side, not with the dorsal surface uppermost. This is 

 so that all parts can be examined, at least on one side. The legs are 

 directed toward the pin, so that they are not so likely to be broken 

 off when the specimen is handled later. It is customary to put the 

 pin in the specimen box in such a position that the point projects to 

 the left. The specimen is mounted so that its head will project forw^ard 

 when the pin is so placed, i. e., its left side is fastened to the point. 



Each specimen should be labeled with the place and date of capture, 

 and the collector's name may be placed on the same label. Such 

 labels are often obtained in quantity from a printer. In such a case 

 very small type should be used. If a small collection is made from a 

 locality, it is ordinarily more convenient to make small labels by hand, 

 with India ink and a crow-quill pen. Additional data (habits, food 



