INSECTA MADERENSIA. 255 



more convex behind : the latter narrowed in front. Elytra as in the last species, only with the 

 two inner costa; not quite so much elevated, and the outer (or submarginal) one proportionably 

 rather more so ; and with the punctures of the interstices, if anything, even larger than those of 

 that insect. Antenna at base, and the legs (especially the tibia and tarsi) more or less paler, or 

 fuscescent. Antenna in both sexes of nearly equal length, and considerably more elongated (in 

 proportion to the size of the insect) than those of the M, oceanicum. 



A well-defined species, and apparently peculiar to the two northern Dezertas. 

 It differs from the preceding one in its smaller and slenderer form, and in its 

 less intensely black hue, in the long, silken, somewhat olivaceous and almost erect 

 pubescence with which it is beset, and by its more infuscated legs and less abbre- 

 viated antennse, — which last are of nearly equal length in both sexes. It appears 

 to be scarce on the Dezerta Grande ; where, nevertheless, I fii-st discovered it,— 

 on the outer canvass of my tent, during the hot sunshine, at the end of May 1850. 

 On the Flat Dezerta, or Illieo Chao, however, it is far more abundant,— where a 

 few days later (i. e. at the beginning of June) it occurred to me in profusion ; 

 principally from amongst the large masses of AVormwood {Artemisia argentea, 

 Herit.) with which that remarkable little island is in certain spots densely clothed. 

 It woLild seem to be less decidedly attached to flowers than the 31. oceanicum ; 

 and indeed less so than is the case with the Ilelyridce generaUy,— in whicli 

 respect, as weU as in many minor details of its economy, it makes an evident 

 approach towards the following family, the Cleridce. 



Fam. 29. CLERID^. 



Genus 91. OPILUS*. 



Latreille, Hist. Nat. cles Ins. iii. Ill (script. Opilo) (1802); 



Corpus mediocre, plerumque lineari-elongatum, vix durum, pubescens, Isete coloratura et punctatum : 

 prothorace angusto, subcylindrico postice leviter constricto : alis amplis. Antenna pilosae, apicem 

 versus leviter incrassatse, articulo primo robusto, secundo brevi, inde ad octavum obconicis lati- 

 tudine subjequalibus, reliquis leviter incrassatis, clavam laxam elongatani baud abruptam tri- 

 articulatam efficientibus. Labrum vix coriaceum, transversum, antice bilobum valde pdosum. 

 Mandibula magnje cornese validffi acutissimse, extus valde pilosa;, infra apicem umdentatfe. 



* Strictly speaking, the title of the present genus is Opilo ; but since it has been usually quoted as 

 Opilus, I have not considered it worthwhile to create confusion by adhering to the original orthography : 

 nevertheless I think it exceedingly questionable how far we are justified in sanctioning the change, so 

 long as other terminations in o (as, for instance, HeUiio, Pi/tho, Tenelrio, Cehrio, Crabro, &c.) are per- 

 mitted to remain ; and whether we do not lay oui-selves open to the charge of inconsistency by smgHng 

 out any one of them as objectionable, whUst,"at the same time, we endorse the rest. A similar absurdity 

 presents itself in Bembidion of Latreille, which is mvariably coiTected into Bemlidium ; and yet Omopliron 

 and Cerylon, of the same author, are retained. If however the Latm terminal is alone admissible in these 

 Greek compounds (and I am by no means prepared to contend that it is not to beprefen-ed, and therefore 

 far letter adhered to in the comage of new generic names), why is it that we countenance such terms as 

 Borcadion, Unnearthron, Pentodon, Urodon, Lymexylon, GymnaHron, Cercyon, &c., which at any rate 

 should be governed by the same law, — be it of rejection or sidferance ? 



