602 INSECTA MADERENSIA. 



incrassatfe, articulo primo elongato robusto, ultimo suboblongo. Labrum transverso-subqua- 

 dratum, lacinia membraneS, triangular! acuminata utrinque (ad angulos anticos) auctum. Man- 

 dihulee validie acutac, longe infra apicem bidcntatre, in medio membrana ciliatil instructs. Maxilla 

 biloba; mcmbranacese : loho externa Icaigiusculo subrecto, apice dense barbato : interna breviore, 

 intus ciliato. Palpi maxillares breviusculi, articulo primo minuto, secundo et tertio subaequalibus 

 apice leviter incrassatis, ultimo minore subulato : labiates articulo secundo breviusculo, ultimo 

 vix subuliformi. Mentum transvcrsum. Ligula lata, apice leviter bisinuata; paraylassis ad 

 apicem liberis acutis, intus dense ciliatis. Pedes breves validi {intermedii distantes) : tibiis (sed 

 praesertim anterioribus) extus spinulosis ; anticis ad apicem externum emavginatis : tarsis 3-arti- 

 culatis, articulo ultimo reliquis conjunctis miilto longiore. 



The almost glabrous bodies of the Flatystheti, in conjunction vnih. their apically- 

 subdeliiscent elytra, their spinulose, biurowing tibiae, triarticulated feet, and the 

 deep central channel of their (posteriorly roxinded) prothorax, will at once serve to 

 distinguish them, apart from the obscurer characters of their oral organs (which 

 will be best understood by a reference to the above diagnosis), from their allies. 

 In addition to the structiu'e of theu' abdominal segments, the males may be 

 usually known from the females by their rather larger heads, — which in many of 

 the species moreover have then* anterior margin armed on cither side v,\\\\ an 

 acute porrccted tooth. They arc insects which are found both in the excrement 

 of cattle and on mud at tlie edges of stagnant pools. I have generally, hoAvever, 

 observed tliem to ha more partial to the latter situations than to the former : and 

 , I have occasionally met with the P. cor nut us, of our owti country, Ijy myriads in 

 the crevices formed by the heat of the sun on the beds of partially-dried ponds. 



§ I. Mandibulce ad apicem integrce. 



471. Platysthetus spinosus. 



P. niger nitidus leviter punctatus, frontc nx canaliculatil, tibiis piceo-ferrugineis, tarsis paUido- 

 testaceis. 

 Mas in insulis Maderensibus adhuc latet (sed differt, sec. cl. Erichson, abdominis segmento septimo 



subtus truncato nccnon ad apicem denticulis duobus distantibus munito). 

 Fwm., capite prothoracis vix latitudine ; abdominis segmento septimo subtus subtriangulariter pro- 

 ducto, ad apicem rotundato integro. 

 Long. Corp. liu. 2^. 



Platysthetus spinosus, Ericb. Oen. et Spec. Staph. 784 (1839). 



Habitat in areuosis Portus Sancti, sub lapide prope oppidum Dccembri mense a.d. 18J:8 a meipso 

 rcpertus. 



P. black, and shining. Head s|iarin£:ly punctured in front, but more closely and deeply so (within 

 the raised lateral margin of the forehead) towards cither side ; w ith a deep rounded fovea on each 

 side of its posterior disk, immediately behind which there is an irregularly curved, or more or 



