504 INSECTA MADERENSIA. 



H. oval (being of almost the same size and outline as the H. cinerascens, but more depressed), usually 

 very densely clothed with dirty brownish mud-like scales, and with the elytra more distinctly 

 striated than in cither of the other species. 



As already mentioned, the S. illotus may possibly be but a local state of the 

 n. cinerascens ; nevertheless, since the Madeiran members of the latter do not 

 appear to differ in any respect (except now and then in size) from those of the 

 neighbom^ing rocks, it is the less easy to assume isolation in the present case to 

 have had sufficient influence to have brought about modifications so perceptible as 

 those which, even at first sight, characterize the former : and yet, on the other 

 hand, it is almost equally unnatural to imagine that an insect so common as the 

 H. cinerascens should not have extended itself to Porto Santo before the separation 

 took place, but should have been represented by a closely-allied form which in its 

 own sphere was no less abundant. Without venturing therefore on the solution 

 of this difficult problem, I would register the H. illotus as distinct, deeming it 

 enough to have recorded my doubts thus far as to its true specific claims. It 

 occurs in profusion throughout all the lower region of Porto Santo and on the 

 adjacent islands, residing in spots precisely similar to those selected by its 

 Madeiran analogue. 



Fam. 48. BLAPSID^. 



Genus 172. MACROSTETHUS, Wall. (Tab. XI. fig. 8.) 



Corpus magnum, elongatum, subcylindrico-ovatum, tuberculatum : fronte ad latera leviter elevata, ad 

 apicem truncata : prothorace ovato basi truncate, fere immarginato : metastemo postice baud 

 Ijifido : chjtris connatis, apice baud acuminatis : alis obsoletis. AntenruB prothorace vix lon- 

 giores, apicem versus seusim iucrassatae, articulo prime leviter robusto breviusculo, secundo bre\'i, 

 tertio longiusculo, reliquis longitudine subsequalibus (articulis apicalibus quatuor, ultimo elongato- 

 subquadrato excepto, subquadratis). Labrum (XI. 8 a) transverso-subquadi-atum, antice valde 

 ciliatum vix emarginatum. Mandihula validse crassse corneae, apice bifidse, intus in medio pro- 

 fundc fisso-sinuat?e. Maxillce (XI. 8 b) bilobse : lobo externa pubescente setoso : interiw apice 

 acutissimo biuncinato, intus valde setoso. Palpi maxillares articulo primo vLx parvo cxtus 

 sinuato, sCcundo elongato subclavato, tertio primo vix longiore, ultimo magno sccuriformi : 

 lubiales (XI. 8 c) e scapis ligula; connatis surgentes, articulis primo et secundo longitudine sub- 

 ajqualibus (illo graciliore, extus sinuato), ultimo crassiusculo pyriformi basi subflexuoso. Mcntum 

 robustissimuui rotundato-subovatum, summo apice vix emarginato. Ligula antice lata, recte 

 truncata et dense ciliata. Pedes longiusculi : tibiis fere glabris, versus apicem internum tenuitcr 

 piibesccntibus (calcariis spinulisque apicalibus obsoletis): tarsis heteromeris; posticis articulo 

 primo longiusculo ; ultimo in omnibus elongato, unguiculis simplicibus munito. 



A /juaKpo'i longus, et aTrjOo'i pectus. 



A most distinct and interesting genus, differing from BJaps in many important 

 particulars, as, for instance, in its tubercidose upper surface, convexer body, ovate 



