INSECTA MADERENSIA. 



477 



A. ovate (being slightly rounded at the sides, and rather li.rrower before than behind), somewhat 

 more convex than the Chjpeaster pusillus, also much blacker and rather more shining, and 

 most minutely punctulated,— the punctures being scarcely perceptible (especially on the pro- 

 thorax) except beneath the microscope. Prothorax rather smaller than in that insect, being 

 scarcely semi-ovate (and therefore with its sides not so parallel behind) ; testaceous in front, 

 where (as in that species) it has also a tendency to be somewhat transparent. Elytra with the 

 punctures rather more perceptible than on the prothorax; and with their extreme apex usually 

 more or less diluted in colouring. Antenna and leffs diluted-testaceous. 



Apart from its generic distinctions, which have been fuUy pointed out, the 

 present insect may be easily recognised from the last by its smaUer and more 

 ovate body, somewhat blacker, brighter, and less depressed surface, and by the 

 excessive delicacy of its punctuation,— which is altogether imperceptible except 

 under a powerful glass. It is perhaps a trifle more pubescent and less shining 

 than the more northern type ; and its punctures, even though thus minute, are, if 

 anything, a Httle more evident. It is apparently scarcer throughout Europe 

 generally than the Chjpeaster pitslllus, being ahnost peculiar to, central and 

 southern latitudes. In Madeu-a proper it would seem to be rare, the only 

 specimen which I have seen having been captm-ed by Professor Heer of Zui'ich, in 

 February of 1851, at the Praya Formoza near Punchal. On the Dezerta Grande 

 however it abounds,— where, at the end of May 1850, I took it in considerable 

 numbers, on the outer canvass of my tent (running rapidly in the hot sunshine), 

 in company with the Europs impressicollis, and other species which have been 

 abeady noticed. It is recorded by M. Lucas in Algeria. 



Genus 158. SERICODERUS. 



Stephens, III. Brit. Ent. ii. 188 (1828). 



Corpus minutissimum,obovatum antice obtusum, sericeo-pubescens, convexum: prothorace ^m^Msmno 

 subluniformi, ad basin elytris latiore, angulis posticis valde productis acutissimis elytra amplec- 

 tentibus, ad latera et (prassertim) antice valde decurvo-producto (caput omnino tegente) : elytris 

 apice truncatis (angulis suturalibus rectis) : alis amplissimis ciliatis. Antenna prothoracis Ion- 

 gitudiue, lO-articulatffi, graciles, clavatae, articulis fere ut in genere praecedenti, sed tertio paulo 

 breviore, et decimo ad apicem externum oblique truncato. Instrumenta dbaria et pedes fere ut in 

 genere pr^cedente, sed tibice apice calcari minutissimo armatse. 



The structm-al characteristics of Sericoderus have been already mentioned,— its 

 short, blunt and anteriorly-dilated oiitline, convex, sericeous upper sm-face and 

 paUid hue, in conjunction with the enormously produced hinder angles of its 

 greatly developed prothorax, its straightly terminated elytra (the sutural angles 

 bemg right angles), and its comparatively slender antennae (the third joint of 

 which is'' not perceptibly elongated, whilst the apical one is obliquely lopped off at 

 its outer extremity), constituting the main distinctive features which separate it 



