iv Preface. 



not, has been fully described according to a uniform plan. A 

 glossary (made very full for the benefit of those unacquainted 

 with entomological terms) is appended. 



The descriptions and figures (unless otherwise stated), have 

 been drawn up from and refer to Ceylon specimens only, and 

 may possibly differ slightly from typical examples in such minor 

 points as size and colour. 



On each plate will be found one figure representing the insect 

 of its natural size, in its natural position on the food plant. The 

 other figures are not drawn to scale, but have been each enlarged 

 to such a degree as to most conveniently show the requisite detail. 

 The actual measurements of each species are given in the descrip- 

 tive letterpress. 



As the metric system is being universally adopted for scientific 

 purposes, I have given all measurements in millimetres (mm.). 

 For the benefit of those who are more conversant with the English 

 standard of inches (") and lines ('"), I have shown a scale of the 

 two systems, by which they may be compared. For a rough 

 comparison, twenty-five millimetres might be taken as representing 

 one inch (the actual figure would be nearer twenty-five and a half 

 millimetres); one hundredth of an inch would thus represent one- 

 quarter of a millimetre (0*25 mm.) ; or one-quarter of an inch 

 would equal six and a quarter millimetres (6'25 mm.). But for 

 ordinary purposes a glance at the figure on the plate representing 

 the natural size of the insect will give the best idea of its 

 proportions. 



Signoret's classical work, the Essai sur les Cochenilks, and 

 Targioni-Tozetti's Italian papers, amongst the older writers ; Mr. 

 W. M. Maskell's many important papers extending through a long 

 series of the Transactions of the New Zealand Institute, and his 

 volume on the Scale Insects of New Zealand; Professor Comstock's 

 first and second Reports on Scale Insects ; are all indispensable 

 to a student of the Coccidse. The scattered papers of Mr. J. W. 

 Douglas and Mr. R. Newstead in the Entomologist's Monthly 



