neiv Species of Coleopterous Insects. 155 



may be avoided ; but it is also to be observed that a series of types 

 of form may certainly be considered to intervene between the 

 P. laticornis and the true Lysh'onychi ; and thus the question which 

 arises whether or not the extreme forms should be regarded as con- 

 generous becomes a point of nice discrimination. 

 Xylophaga. 

 Fam. BosTKicHiD^., Leach. 

 Genus Platypus, Herhst. 

 Platypus (Tesserocerus) insignis. Plate XIV. fig. 6. 

 Cylindricus, piceus, capita thoraceque nigricantibus, elytris rufo- 

 piceis, postic^ obscuris. 



Long, corporis 4 lin., lat. I-^ lin. 

 Habitat in Brasilia circum Monte Video. 

 In Mus. nostro. 



Descr. Antenme piceo-flavse, diiFormes, sex-articulatae, articulo 

 primo longissimo recurvo, infra piloso, ante medium geniculato, 

 et pro frontem insigniter recurvato, apicem versus dilatato de- 

 flexo, subttis ciliato ; articulis quinque reliquis in primum ad 

 geniculam oblique insertis, 2 — 5 brevibus (magnitudine de- 

 crescentibus), ultimoque maximo, complanato, subrotundo, 

 patelliformi, pi Us (nisi basi) obtecto (fig. 6. a.). Caput nigrum, 

 pilis longulis fulvis ad frontem prosistentibus dense vestitum. 

 Thorax niger, maculis duabus contiguis minimis (e pilis luteis 

 formatis) basin versus notatus. Elytra rufo-picea, postice 

 nigricantia, props apicem abrupte depressa ; singula lineis qua- 

 tuor (quarum quarta parum distincta) vix elevatis compressis, 

 interstitiis crenato-striatis, totidem in dentibus ad apicem pro- 

 ductis, suturalibus utrinque maximis ; apice ipso pilis fulvis 

 obsito. Cor/?MS infra piceum, pectore pallidiore. Pedes •picGo- 

 fulvi, geniculis nigrescentibus ; femoribus crassis ; tibiis per- 

 brevibus, transverse sulcatis, ad marginem denticulatis, et in 

 spinam fortem ad apicem productis. Tarsi ut in Platypo 

 cylindro, articulo tertio baud bilobato, penultimo (4to) minu- 

 tissimo (fig. 6. d.). 



With the exception of the species of the genus Paussus, there is 

 no coleopterous insect with which I am acquainted possessing such 

 remarkable antennae as the present. In many respects indeed they 

 closely resemble the antennae of Platypus cylindrus, &c., but with 

 this very obvious difference, that the long basal joint, after giving 

 rise to other joints of the same peculiar construction as those of 

 Platypus, forms a sort of knee, and becomes considerably prolonged 

 in a curvilinear direction, extending itself before the front of the 



