270 



CURCULIONID^E. 



ture to assume its identity (or at least its relationship) with the 

 former, and embody it in the text of this volume placing it where 

 I now do. Still, in reality, I know no more about it than 1 did 

 formerly, and can therefore give no information as to the island in 

 which it was captured ; though, as the illustration of it and specific 

 description equally prevent my referring it to any other Curculionid 

 which has hitherto been met with in these Atlantic islands, I think 

 perhaps we may conclude it to be at all events Canarian, and await 

 the detection of future material to supply us with a knowledge of its 

 undoubted affinities and its exact habitat. I may, however, just add 

 that I am more inclined to suspect that it will prove ultimately to 

 be a variegated Acalles than a Mononychus. 



Genus 242. ACALLES. 

 Schonherr, Cure. Disp. Meth. 295 (1826). 



The excessive variability of most of these Atlantic Acalles renders 

 it next to impossible to give satisfactory diagnoses of them which 

 shall define accurately the respective limits of their variation. Yet 

 when examined with the aid of large numbers for comparison, they 

 may usually be well enunciated in a general way, though the defi- 

 nitions can scarcely be made, even then, without great difficulty, to 

 include within them occasional specimens which either depart from 

 their respective types or which (more frequently) are in such a bad 

 state of preservation that their true characters (of colour and clothing) 

 have become nearly obliterated. Individuals indeed such as these 

 last referred to, the collector would do well to destroy ; for they only 

 tend to perpetuate confusion by appearing to connect species which 

 are in reality well expressed, and under one or the other of which 

 they would themselves unmistakeably fall were they sufficiently 

 perfect to render all their external features appreciable. 



The practical naturalist will not misunderstand these remarks, or 

 suppose for a moment that I would wish to solve difficulties by 

 simply ignoring them. They do not apply to variations (as such), 

 in any form or shape, but simply to the retention of material (in 

 these scale-covered, inconstant creatures) which is absolutely worthy 

 less on account of its having lost the main characteristics on which 

 we are often compelled to rely in framing our several diagnoses. I 

 am fully aware how difficult it is in some few instances, even with 

 the best of material, to determine critically where one species may 

 be assumed to end, and another to commence; yet I positively 



