Although the title exhibits a concise view of the object and proposed contents of this work, it may be proper, in accordance 

 with established custom, to give some additional details, explanatory of the materials whence it will be produced, the method 

 to be pursued in the treatment of the subjects, the extent of the work, and finally the mode of publication proposed. 



The subjects which it will bring before the public are arranged in the Museum of the Honourable East-India 

 Company. They consist principally of a general series of Lepidopterous insects from the island of Java, accompanied 

 with an extensive set of drawings representing their metamorphosis, the history of which is detailed in the Introduction. 

 To this will be added various subjects contained chiefly in a collection of insects from Ceylon, presented by M. Jionville, 

 and in a smaller miscellaneous collection from continental India, presented by Claude Russell, Esq., the brother of 

 Dr. Patrick Russell. It is likewise my intention to include such additions as may be made from time to time to the 

 Museum during the progress of this work, from the territories of the Honourable Company in the Eastern World. 



The work will be published in royal quarto, and consist of six parts, containing each about eighty pages of letter-press ; 

 the distribution of the subjects being the following : . 



Part I. Introduction : detailing the outline of a general arrangement of Lepidopterous insects according to their 

 metamorphosis. Description of the first tribe or of the Lepidoptera Diurna. Stirps the first, with Vermiform Larva. 

 Genera Polyommatus and Lycana. 



Part II. Conclusion of the Vermiform Stirps. Second Stirps of Lepidoptera Diurna with Chilognathiform or Iuli- 

 form Larvje. Third Stirps with Chilopodiform or Scolopendriform Larv.e. Fourth Stirps with Thysanuriform 

 Larvje. 



Part HI. Fifth Stirps of Lepidoptera Diurna, with Anopluriform Larv.&. 

 Second Tribe of Lepidoptera or Sphingid^;. 



Part IV. Third Tribe or Bombycid^e. 



Part V. Fourth Tribe or Noctuid-E. 



Part VI. Fifth Tribe or Phauenidje. 



Each part will be illustrated by four plates consisting of highly finished engravings by artists of eminence. Three of these 

 will be coloured with accuracy and elegance ; the fourth more elaborate as an engraving will be given plain. A limited num- 

 ber of copies with proof impressions, and the whole of the plates coloured will be published at a proportionally advanced price. 



The first plate is devoted to the illustration of new species, and such subjects will be preferred as are typical of the 

 groups defined in the progress of the work : they will be arranged, as faT as possible, according to their affinities. For the 

 second plate, those subjects will be chiefly selected which form types of genera ; and they will, in most cases, be accompanied 

 by dissections. On the third and fourth plates the history of the metamorphosis will be elucidated, and they will likewise 

 contain additional generic illustrations and dissections. The plates of the first part exhibit a specimen of the plan projected 

 for the whole ; and here may be added, that for the succeeding parts the materials are equally copious. 



As to the plan of the descriptive part, a very concise outline can only be given in this place. The arrangement proposed to 

 be followed and the constitution of the higher divisions, namely of tribes and stirpes, are explained in the Introduction. These 

 are defined from a review of the whole order : but the sections indicated either in the stirpes or in the genera are provisional only, 

 as they are regulated by the extent of the collection. A detailed generic character is given in the Latin language ; this is followed 

 immediately by a somewhat amplified description in English. Every species is distinguished by the generic and specific name 

 at length. This is followed by a Latin description, in technical language, intended to exhibit a concise but accurate delineation 

 sufficiently minute to afford the means of precise discrimination from all other species. In the English description of new spe- 

 cies the object is to give a full history of the external character in all its details. It is not consistent with my present plan to give 

 specific characters according to the Linnean models : these belong, in my opinion, to works in which a general comparison of 

 species contained in extensive collections, enables the writer to define the characters with a precision and confidence which 

 cannot be obtained in the examination of a mere local collection. 



The detailed specific descriptions will be followed, in most cases, by a series of miscellaneous observations. In these it is 

 my chief object to illustrate the history of those individuals, which I have traced through their various stages of existence, and 

 of which our collection contains representations in their larva and pupa states. The arrangement projected for this 

 work being founded primarily on the metamorphosis of the insects of this order, this part of the subject will be found to have 

 an important bearing on the whole. These observations will also afford the necessary explanations of the figures contained on 

 the third and fourth plates, and they will lead to the detail of the remarks made on the food »of the larva, the season of the 

 year when found, their abundance or scarcity, and to such other peculiarities as may have been noticed in Java. Under this 

 head I shall also give an account of the state of the collection regarding the materials from which the descriptions have been 

 made, with the view to illustrate many doubtful or imperfectly known species. The public or private collections in this 

 metropolis, in which the species described may have been observed, will also be indicated : and finally their range through 

 other parts of India : and in the whole of these miscellaneous observations, as well as in the generic and specific descriptions, 

 a principal object will be to render the work generally useful and Interesting to the British naturalist. 



The parts will follow each other with every degree of expedition consistent with the preservation of the style of publica- 

 tion, in which the work has been commenced. Those preparatory arrangements which are inseparable from every under- 

 taking of this nature have in some measure retarded the first part, but the publishers are enabled to engage, with every pros- 

 pect of success, a regular continuation of the work : accordingly we announce the appearance of the second part early in July 

 next, of the third, at the commencement of the ensuing year, and of the remaining parts at intervals of six months. Accord- 

 ing to this plan, the whole will be completed within three years from its commencement. 



Some objection may perhaps be made to the length of the Introduction and to the extent of the descriptions with which the 

 work commences. In explanation of the former I shall observe that a general plan having been sketched, and the limits of the 

 higher groups having been defined, the systematic details will be greatly abridged in future. Regarding the plan of the 

 descriptions, it will be obvious to the carefulobserver that the subjects which presented themselves at the commencement were 

 either new or imperfectly known, they therefore required a more copious detail than will be found necessary in less interesting 

 cases ; but I may be allowed to state clearly, that in the progress of the work, well known species will be introduced with a 

 very concise notice, and the descriptions throughout will be accommodated to the plan and extent of the work proposed at the 

 commencement of tins Prospectus. *^ *^ 



T. H. 



