viii PREFACE. 



many cases we have been compelled to limit our notices to little more than 

 the characters by which the objects are distinguishable in their respective 

 classes, &c. This has always been a great point in the composition of the 

 work to enable the microscopic observer to discover what any object is 

 which may be presented to him, and by the aid of the Bibliography to refer 

 to more extended treatises for further details. 



Our thanks are again due to those who have kindly lent us aid, especially 

 to Mr. Dallas for the articles Aphidae, Chalcididse, and Cynipidae; and also to 

 those who supported us by their friendly notices of our former labours. 



J. W. G. 



December 6, 1859. 



PREFACE TO THE THIRD EDITION. 



AT last the third Edition of the ' Micrographic Dictionary ' is completed. 

 But I feel that some explanation, or even apology, to the Subscribers is 

 requisite, considering the delay that has occurred in its issue. To ill-health 

 and press of prof essional engagements this is attributable. For some time, 

 being constantly in the hope of rapidly completing the work, I hesitated to 

 place it in other hands, until at last I found it essential to do so. The editing 

 of the work subsequently to the letter H was therefore transferred to Prof. 

 Duncan, whose name will form a sufficient guarantee that it has been satisfac- 

 torily accomplished. 



In regard to the alterations made in this Third Edition, it will be noted 

 that nearly 100 pages of new matter have been added. The original articles 

 have been revised according to modern researches and views, so as to 

 represent, as far as space would permit, the present state of knowledge. 



When I state that the Articles upon the Fungi were intrusted to the 

 Rev. M. J. Berkeley, and those upon the Foraminifera to Prof. Rupert Jones, 

 the reader will surely feel confident that they have been carefully and 

 faithfully elaborated. For some valuable notes on the Lichens I have to 

 thank the Rev. W. A. Leighton. 



An important novelty in this Edition consists in the accentuation of the 

 names forming the headings of the articles. The classical pen of the Rev. M. 

 J. Berkeley has afforded aid upon this point also. 



The Plates have all been newly engraved upon copper, thus rendering the 

 figures of the objects more sharply defined. Three new plates have been 

 added, and several of the original Plates have been re-arranged and improved. 



J. W. G. 



December 2, 1874. 



