VI IITTEODUCTOKY REMARKS. 



I spent six weeks by myself in Teneriffe — principally in the higher 

 districts towards the Peak, and ascending to the lower limits of the 

 snow. It was during this short interval that some of my most valu- 

 able material was accumulated ; and I look back to that brief sojoiirn 

 in those wild upland tracts — amongst full-blown " Eetamas " of de- 

 licious fragrance, far above the cloud-line, in what an entomologist 

 might strictly call " an apiarian heaven " — as embodjang reminis- 

 cences, of sight and sense, which none but those who have revelled in 

 such scenes can truly appreciate. 



In addition to my own material thus amassed (including, at least, 

 some 20,000 specimens), and that obtained by Mr. Gray in January 

 and February of 1858, I have had the advantage, while compiling 

 this Catalogue, of several smaller collections which have been sub- 

 mitted to me. Of these, by far the most valuable and important was 

 formed by Dr. Crotch during the spring of 1862 ; and to his accurate 

 and indefatigable researches (to which I shall often have occasion to 

 allude) nearly 50 additions to the fauna are entirely due. Much 

 useful material has likewise been communicated, from time to time, 

 by my excellent and worthy friend the Barjio do Castello de Paiva of 

 Lisbon, who has spared no pains to prociu'e specimens, which he has 

 on every occasion, with characteristic generosity, placed at my imme- 

 diate disposal. From Professor Heer also, of Zurich, I have received 

 many types of the species from which he prepared the list for 

 M. Hartung's volume on Lanzarote and Fuertevcntura ; and, indeed, 

 M. Hartung himself allowed me to select a certain number of them 

 from his boxes, when I chanced to meet him in Madeira, on his 

 return from his Canarian explorations. And I am happy to be able 

 to add that the various novelties which have been brought to hght 

 from these different sources I have been permitted, through the 

 liberality of their several possessors, to place in the National Col- 

 lection. 



Feeling the paramount importance, in a Catalogue like the present 

 one, of themos^ thorough accuracy in the faunas of the separate parts 

 of the Group, I should state that I have used the utmost caution in 

 the insular distribution of the various species enumerated. In all 

 cases where the existence of the latter in any particular island rested 

 upon doubtful evidence, I have preferred theirnon-admission into that 

 island's fauna to the risl- of a possible error (even though that risk 

 were, practically, almost nil). And I hope it will not be considered 

 presumptuous if I record my conscientious belief that no single mis- 

 take has occurred in the Topographical Index of this volume. Indeed 



