138 Mr. T. Vernon Wollaston on the JiJtjphorMa-infcstlng 



the (lead Enphorhia-stems, whenever they chanced to occur ; and 

 durinw my subsequent visits to the islands it has always been one 

 of my chief objects to investigate them. 



What I propose in the present Memoir, is to describe allf the 

 species of the Coleoptera which have hitherto been ascertained to 

 occur amongst the various Canarian Euphorbias. Although the 

 greater portion of them would seem to be attached exclusively to 

 those plants, a few (as might indeed be expected) occur in others 

 likewise ; but since my object is to place before the collector the 

 exact insects which he would probably meet with whilst searching 

 the Euphorbias, I am compelled to admit this small assortment 

 which are not entirelij of Euphorhia-'m^es\\r\g habits. Such species, 

 however, are not numerous ; for out of the forty-eight enumerated 

 below, thirty-six I are apparently quite peculiar to the Euphor- 

 bias, — the remaining twelve only displaying more promiscuous 

 modes of life. 



But however remarkable may be the perfect exclusiveness of an 

 immense majority of these Culeoplera to the rotten Euphorbia- 

 stems, it is not more so than the prodigious numbers in which 

 many of them occur. The Europs impressicoUis , I'hlceophagus 

 caulium and Mesites fusiformis occasionally swarm within the 

 branches and trunks ; and the Aphanarthn abound to such an incre- 

 dible extent that I have often seen decayed stalks almost, as it were, 

 alive with them. In fact, at the present moment, I cannot recall 

 having ever found a single dead Euphorbia, even though it chanced 

 to be the only one remaining in a district, and miles removed, so far 

 as I could judge, from any other shrub of the same genus, which 

 was not tenanted by one or more species of AphanarUnmi ; and 

 yet one may search the archipelago from end to end, at all eleva- 

 tions and in every conceivable position, without detecting so much 

 as a solitary individual attached to any other plant! 



Here then surely, if ever, we have a good opportunity for test- 

 ing, by actual observation and on an extensive scale, the effects 

 (did such exist) so ingeniously pleaded for by a certain modern 



t One only has been omitted, — a most extraordinary and anomalous little 

 insect with curiously dilated gencB in the male sex, strictly Rhyncophorous 

 trophi (with the exception of a fully developed upper lip), and (as I believe) 

 pseudotetramerous feet; but as Prof. Westwood is working at presant at Platy- 

 cephalous Coleiiplera, I have handed over to him this remarkable creature (to 

 which I had applied the provisional name of Thaumaitocephulus lobains) for in- 

 sertion into his Paper. 



i I have indicated these thirty-six, in the following diagnoses, by affixing an 

 asterisk to thsin. 



