476 INSECTA MADERENSIA. 



with the diminutive insects of which the present family is composed, — since their 

 general lineaments, in connexion ^vdth the great variety displayed both in the 

 num1)er and proportions of their antenna! joints, at once afford a series of com- 

 binations which may be readily grasped. 



Apart fi-om the distinctive peculiarities of its oral organs (wliich, though trivial, 

 do nevertheless exist, — as a comparison of the respective figures, and a glance at 

 the above diagnosis, will easily demonstrate), Arthrolips may be known from 

 Chjpeaster by its inferior size, otate and more anteriorly acuminated body, and by 

 its shorter antennfe and legs, — the former of which, like those of Sericodcnis* , 

 are 10-articulate, and have the five minute joints between the second and the club 

 of subequal breadth (the first of them however being perceptibly longer, and the 

 last altogether a trifle larger, than the intervening three), and the clava itself 

 loose, elongated and perfoliate : whilst from Sericoderus it may be recognised by 

 its totally different configuration, — its prothorax being small, comparatively narrow, 

 and with the posterior angles nearly right angles ; whereas the prothorax of that 

 genus is enormously developed (being considerably -^^-ider than the elytra), and has 

 its basal angles, as in many of the Ptiliadce, immensely lengthened and acute. In 

 Arthrolips and Chjpeaster moreover the body is somewhat depressed above and 

 roimded beneath, the colour is dark, with the front edge of the pronotum (which 

 is slightly elevated) alone pale, and the elytra (especially of the former) are sub- 

 obliquely truncated at their extremity (each of them being a little Ijlunted, or 

 dehiscent, at the suture) ; whereas Sericoderus is convex on the upper side and 

 flattened on the under, its surface is sericeous and of a uniformly pallid hue, the 

 anterior margin of its pronotum has no tendency to be recurved, and its elytra are 

 terminated straightly (the inner angles being right angles). 



365. ArthroUps piceiun. (Tab. X. fig. 6.) 



A. ovatum subconvexiim nigrum pubescens et subtilissime punctulatum, prothoracis limbo antico 

 pallido subpellucido, anteniiis pedibusque diluto-testaceis. 



Long, coi-p. lin. \. 



Cli/peasfer 2>!ceus, (Kimze) Comolli, De Col. Nov. 50 (1837). 



ohscurus, Dej. Cat. (3'*»« edit.) 455 (1837). 



piceus, Lucas, Col. de VAlgerie, 551 (1849). 



Grifphinus piceus, Eedt. Fna Austr. 574 (1849). 



Habitat Maderam, rarius, a cl. Dom. Heer adPraya Formoza prope Funchal mense Februario a.d. 1851 

 detectum : in Deserta Grandi tamen abundat, qua Male exeuntc a.d. 1850 copiosissime coUegi. 



* Although possessing the same number of joints, the antennje of Arthrolips and Sericoderus are never- 

 theless not altogether coincident,— since the third articulation is distinctly longer in the former genus 

 than in the latter ; ;vhilst the terminal one has no appearance in Arthrolips of the oblique truncation 

 which is so evident in Sericoderus. 



