Genus Dorysthenes, 515 



cundo brevissimo subhaemisphaerico, tertio longissimo subcylin- 

 drico, ca2teris ad penultimatn iDclusam gradatim breviscentibus 

 subtrigonis apice cyathiformibus, ultimo subelongato, processu 

 ovali brevi, tridecimum articulum fere repraesentante, ad apicem 

 instructo. 



MandibulcB graciles, porrectas, subelongatae, ad basin tuberculo 

 subeniinenti, denteque parvo acuto instructas, per reliquam longi- 

 tudinem inermes, subtrigonae, intus incisoriae, corapressissiraae, 

 paululum arcuatae. 



Palpi maxillares quadriarticulati ; articulis tribus primis sub- 

 cylindricis subcompressis apice crassioribus, primo et tertio fere 

 aequalibus subbrevibus, secundo longiori, quarta securiformi : la- 

 biales triarticulati ; articulis duobus primis subcylindricis sub- 

 compressis apice crassioribus, primo subbrevi, secundo longiori, 

 tertio subbrevi securiformi. 



Pedes mediocres,f etnoribus iibmqne valde compressis. 



Corpus subelongatura, subcylindricum. Collum productura. 

 Thorax subrhomboideus, ad latera unidentatus, marginibus acutis 

 compressis. Sternum forte, in spinam validam productura. 



This form stands conspicuously distinct from any other that I 

 have hitherto observed in the family of Prionidw. Its somewhat 

 lengthened and subcylindrick body, its elongated neck, its slen- 

 der porrected and unarmed mandibles, and above all its armed 

 sternum^ produced into a strong and acute spine, offer characters 

 which call for a separate station and title in the family. The 

 Prionidw are at present in such confusion, little having been 

 done to subdivide or regulate the various and strongly marked 

 groups which are still included in the genus Prionus, that it is 

 impossible at present to point out the affinities of Dori/sthenes, 

 or to ascertain its relative station in the family. 



I have seen but one species that accords with the above charac- 

 ters, which although a well known Fabrician species, and figured 

 by Olivier, I think of sufficient interest from its peculiarity of 

 form, and also its scarcity, to have figured in this journal. 



2 K 2 



