98 PROCEEDINGS OF THE AMERICAN ACADEMY 



nearer approach could be made toward the dates of the different parts 

 of the book by a comparison of the moths with those of the Zutriige. 

 These facts are given to show that the whole work could not have 

 been published in 1816. Still, for mere convenience and uniformity, I 

 have used 1816 as the date; for the only case where the dates conflict 

 with those pf another writer in the use of the same generic name is 

 that of Eurybia, which should unquestionably be referred to Illiger. 



The preceding statement also shows that the dates of the different 

 parts of the Zutrage are probably correct. 



The Tentamen* is undated. It is twice referred to by Hiibner him- 

 self: once in the preface to his Verzeichniss, written in 1816; and again, 

 in 1818, in the preface to the first century of his Zutrage. In the latter 

 case it is not specified by name, but the substance of it is reprinted, 

 and there is no other work of Hiibner's to which his words can refer ; 

 it is stated to have been published in 1806. It is also referred to by 

 Ochsenheimer in 1816, in the preface to the fourth volume of his 

 Schmetterlinge Europas, as having been unknown to him at the time 

 of the publication of the first volume of the same work, in 1807 ; it is 

 also included by Geyer in his list of Hiibiier's works, and by Hageu 

 in his Bibliotheca Entomologica. 



I am greatly indebted to Dr. Hagen, of Cambridge, and to Herr 

 Gerichtsrath Kefersteiu, of Erfurt, for their kind assistance in my 

 endeavor to discover the dates of Hiibner's works. It would be a 

 worthy task, if one of the Berlin entomologists would examine the works 

 of Hiibner in the Konigliche Bibliothek, where, I am told by Dr. 

 Hagen, they are preserved in their original wrappers. 



There is still another work, the dates of the different parts of which, 

 as given here, require explanation. Doubleday and Westwood's Genera 

 of Diurnal Lepidoptera was published in parts, and Mr. B. P. Mann has 

 shown me a nearly complete set of the work in the original wrappers ; 

 although it is the reissue and not the original edition, a careful com- 

 parison of its divisions with the dates printed at the bottom of many of 

 the signatures, convinces me that the reissue was purely a reissue, and 

 that the plates accompanying each part of the text are the same as in 

 the original issue. The dates given below are based upon this suppo- 

 sition. 



The dates of different parts of such of Boisduval's works as appeared 

 by livraisons are drawn from the official literary bulletin published in 

 Paris at that time, and can be relied upon for accuracy. 



* Kepublished by me in foe-simile. Cambridge, 1873. 



