120 BULLETIN 67, UNITED STATES NATIONAL MUSEUM. 



in diameter, provided with a screen cover, are suitable receptacles. 

 Whenever possible one should try to obtain the pupae, as results are 

 more certain, and in several families the larval exuvia is retained in 

 the pupal case, and can be compared with larvae collected at the 

 same place. With other species occurring in running water it will 

 be necessary to supply them with running water, or else to place a 

 small cage over a larva in a stream and await its development. 



SHIPPING INSECTS. 



Entomologists increase their collections largely by exchange. A 

 collector in one part of the country writing to one in another tells 

 him what he wants and what he has to offer in exchange. These 

 lists are called "desiderata" and "offerta." Sometimes, in exchang- 

 ing, collectors use the numbers of some recognized catalogue instead 

 of writing out the names. It is customary in sending to number 

 the specimens and in the letter give the list of numbers with the 

 names. In exchanging, one should endeavor to send as good speci- 

 mens as possible, neatly mounted and labeled and carefully packed 

 in secure boxes. Most insects are fragile, and one must use great 

 care in packing them. The specimens should be securely pinned 

 in the box, but not hammered down. If there are any with large 

 bodies or long, slender abdomens, these parts should be braced by pins 

 placed crosswise. The top of the box should be so fastened that it 

 can not be easily mashed in. A strip of wood is sometimes fastened 

 on the inside at the top of the box to give further support to the 

 cover. The box should, if sent by mail, be wrapped, not too tightly, 

 in cotton or excelsior about 1 inch thick around it. However, it is 

 better to put this box into a larger box, with 1 inch space or more each 

 side, and this is filled, but not too tightly, with cotton or excelsior. 



Sometimes a little cotton is placed around the outside of the outer 

 box. Most Coleoptera, Hemiptera, and Hymenoptera are not very 

 fragile, and a good wrapping of cotton or excelsior is all that is neces- 

 sary. With Lepidoptera, Neuroptera, and Diptera one can not te 

 too particular in packing. The Lepidoptera and Neuroptera are 

 more safely shipped in papers in a tin or wooden box; then there 

 is no danger of breakage. 



If one has a box of specimens as large as an ordinary cigar box it 

 had better be sent by express, especially if it contains fragile insects. 

 There should be at least 2 or 3 inches space between the cigar box 

 and the outer box; the latter should be a stout one and the space 

 lightly filled with excelsior; never try to cram in all the excelsior you 

 can, but only enough to keep the box securely in its place. It is 

 much better to screw the top on than to nail it, as the jar in nailing 

 may break or loosen something. The handiest way to ship by ex- 

 press is to use a flat half-bushel basket, packing it with excel- 



