XXV111 



INTRODUCTORY REMARKS. 



Sand-infesting Coleoptera. Seeing that the whole of these Atlantic 

 Groups are of volcanic origin, and more or less mountainous in 

 character, we should not anticipate the existence of those particular 

 localities which are favourable for species of sand-infesting habits ; 

 and accordingly in most parts of the archipelago (as, for instance, 

 the central and western ones) we find but few traces of them. Yet 

 there are districts, nevertheless, towards the east, both in the 

 Madeiras and Canaries, which present all the conditions supposed to 

 be necessary for creatures of that peculiar mode of life, and which 

 so far resemble the low and sandy tracts on the opposite coast of 

 Morocco as to introduce a sub- African element into the fauna. Such 

 regions as these constitute a very significant feature, not only in 

 Porto Santo (where the beds of calcareous sand which undulate 

 around the base of the mountains are sometimes extensive), but 

 likewise in Lanzarote, Fuerteventura, and Grand Canary, in each of 

 which there are districts bordering upon the sea- shore which are 

 entirely covered with loose drifting sand often accumulated into 

 hillocks and slopes of considerable dimensions, and more or less 

 studded with such few plants as are able to maintain themselves in 

 those arid wastes. We may therefore, for the sake of accuracy, 

 class under the two following heads the species of the particular 

 districts in question (each of which, in a general way, differs 

 somewhat from the other: (1) those which occur (beneath marine 

 rejectamenta, &c.) along the edges of the sea, or in other brackish 

 spots, and which are principally of subsaline habits ; and (2) those 

 which are found either on the dry sandy hillocks and ridges which 

 commence behind the actual beach, and which often extend to some 

 little distance inland, or in the calcareous localities which are situ- 

 ated for the most part at a distinctly higher (though seldom at a 

 very high) elevation, and in which the triturated sand is liable to 

 become deposited in the inequalities, or depressions, of the exposed 

 weather-beaten surface. Although the regions which I would thus 

 define are apt to merge into each other, they are nevertheless, in a 

 broad sense, so opposite in character that what I term the " sand- 

 infesting Coleoptera" could scarcely be enumerated satisfactorily 

 without some rough explanation (such as the above) concerning the 

 nature of their respective habitats having first been given; and 

 therefore in the subjoined list I have added the numbers (i) and 

 (2), according as required, after each of the species, so as to afford 

 an idea (occasionally, however, only approximate) of the kind of 

 places in which the latter are normally to be found. The 13 which 



