2 PROCEEDINGS OF THE NATIONAL, MUSEUM. vol.60. 



New Zealand Department of Agriculture,^ and the generous recom- 

 mendations made by the last to the New Zealand authorities so re- 

 sulted that the final consignment of the collection reached Washing- 

 ton in 1909. Studies on the collection were begun under the direction 

 of Doctor Marlatt immediately after its arrival, and various notes 

 were made and photographs taken of the more important species, but 

 uncontrollable circimistances have, up to the present, prevented the 

 extended critical study of the species which is much needed to fur- 

 tlier the classification of the Coccidae, and have also prevented the 

 preparation for publication of such notes and studies as had been 

 made previously. 



When an opportunity recently presented itself to the writers to 

 undertake definite work on this collection, it was decided, after some 

 consideration, that the redescription and redefinition of the different 

 genera based on Maskellian species was the most immediately im- 

 portant work which could be done, in spite of-the fact that it required 

 studies of genera scattered promiscuously through the whole family, 

 and gave little or no opportunity for correlative classification in any 

 group. These studies have certainly opened up more questions than 

 they have been able to settle ; however, it is hoped and believed that 

 they will further the beginning which is being made in the study of 

 the classification of this diffcult family along lines leading away from 

 the superficial and conspicuous characters heretofore depended upon 

 to indicate relationships, and toward those fundamental similarities 

 and differences, often minute, in the structure and biology of the 

 species, which must sooner or later be relied upon if a true classifica- 

 tion is to be developed. 



In the following descriptions, and particularly in the diagnoses of 

 the genera, the writers have, in all probability, overemphasized many 

 structural details which will be found on extended comparative study 

 of the different groups to have little value for generic differentia- 

 tion. The field is so large that a thorough knowledge of the com- 

 parative anatomy of the members of the family can only come in 

 piecemeal fashion, and it has in consequence been considered prefer- 

 able to err through the inclusion of unnecessary details rather than 

 through the omission of possibly important facts. 



The studies of the type species have been confined almost entirely 

 to the various stages of the female, and principally to the adult and 

 the first-stage larva. While there is no reason for believing that a 

 study of every stage of both sexes of a species will not contribute 

 something to a knowledge of its relationships, practical considera- 

 tions, chiefly the question of the volume of this paper, the fact that 

 the two stages emphasized are the ones most frequently obtained in 

 collections, and the fact that in the case of the male sex there is no 



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