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and dust; grease frequently causes the entire disappear- 

 ance of markings that, after treatment with chloroform or 

 other grease-absorbing liquids, again become quite distinct. 

 Specimens mounted on cards when wet, or with very watery 

 gum, frequently also apparently lose their markings; and it 

 is not always easy to restore them, as the amount of soaking 

 and brushing necessary tends to abrade the pubescence : a 

 slight amount of grease or dirt also may obscure the generic 

 details on the hind legs of Mordellistena (especially of the 

 dark species). In some specimens also the point of view, 

 especially in relation to the pronotum, may make consider- 

 able apparent difference. A change from silvery (or white) 

 to golden (or stramineous) is of no specific value, and seldom 

 even of varietal ; moreover, golden markings (with age or 

 after lengthy immersion in liquids) frequently lose their 

 gloss, and white markings under similar circumstances fre- 

 quently become yellowish. On many species parts of the 

 legs are reddish, but the amount of red is frequently liable 

 to sexual and even individual variation. The shape of the 

 pygidium is also liable to sexual alteration, and its apparent 

 shape by the greater or less extent to which it is clasped by 

 the abdomen. On most specimens the antennae are difficult 

 to examine clearly, and even when so seen their apparent 

 proportions alter with the point of view. Any worker at 

 the family, with an abundance of material, is certain to 

 have many specimens that might be referred to any of several 

 species, hence it is desirable to leave such specimens unnamed 

 (or at least queried) ; this is especially the case with the 

 allies of promiscua and of baldiensis. 



The number of species now known from Australia, 

 although large, probably represents but a small proportion 

 of the actual number existing, as many species appear to 

 occur only on flowers on tops of tall trees (and it is this 

 fact that makes the collection from Mr. Dodd of special 

 interest). As yet very few species have been recorded from 

 the Northern Territory, the interior, or the North-west, and 

 it is unreasonable to suppose with species occurring in 

 abundance elsewhere, that there are not many species also 

 in those parts. They are attracted by flowers of almost 

 every kind of plant (even of grasses and of everlastings), 

 and on many kinds of flowers they frequently swarm in 

 immense numbers, many species being often mixed together. 

 The close general resemblance of the species to each other 

 have probably caused many collectors to refrain from making 

 special efforts to obtain them, and the lively habits and small 

 size of many species have also, no doubt, contributed to their 

 escaping capture by collectors. 



