Biology of the Membra cidae of the CA-iTjoA Lake Basin 431 



METHODS OF PRESERVING 



For the permanent collection, adults were invariably pinned and nymphs 

 were preserved in 70-per-cent alcohol. In some cases the nymphs of the 

 last instar were preserved in both ways, som_e in alcohol and some on 

 pins. 



No special dhections need be observed in pinning the local forms of 

 the family, l)iit in the preparation of exotic material in which characters 

 are found in the trochanters it is very necessary to pin the specimen 

 in such a manner that these appendages will not be destroyed. 



The principal characters necessary for the recognition of the local 

 forms are found on the head, the dorsal crest, and the wings. If, therefore, 

 the pin is placed directly downward thru the prothorax on one side of 

 the median dorsal hne, it will usually not interfere with the structures 

 needed for diagnosis. It has been found very convenient to mount 

 a few individuals in each series with their wings spread out or at least 

 removed from beneath the margin of the pronotum, since in a number 

 of genera the cells of ■ both the fore and the hind wings are used in 

 systematic work. 



The use of points is not to l^e advised in mounting Membracidae, since 

 if the insects are securely glued to the point the abdomen and the femora, 

 and even the beak, are Ukely to be hidden, and, as has been noted, these 

 structures are often valuable in making determinations. 



Species that are too small to be easily moimted on regular pins may 

 be satisfactorily mounted on ^ninuten nadeln, which have all the advantag(\s 

 of points without the disadvantage of obscuring any part of the Ijody. 



Individuals taken in copula are mounted on the same pin if large and 

 on two nadeln on the same pin if small. 



Date, locality, and host laljels are placed on each pin if the data are 

 available and the insect is intended for the permanent collection. No 

 record has been kept of the particular station where the specimen was 

 taken except in the field notes, and this record is not attached to individual 

 specimens. 



Nymphs may be kept indefinitely in 70-per-cent alcohol. The last two 

 instars may be mounted on pms and preserved in fairly good shape, 

 altho they are likely to dry out ^md are unrelial)le for use in making com- 

 parative measurements. 



