INSECTA MADERENSIA. 39 



filiformes, capite protlioraceque paulo longiores, articulo primo sequentibus robustiore, secundo 

 brevi. Labrum traasverso-quadratum, antice vix emarginatum et setis paucis longissimis in- 

 structum, angulis anticis rotundatis ciliatis. Mandibulce incurvje acute, intus basi denticulatse. 

 Maxilla bilobse : lobo externo palpiformi biarticulato : inteimo acuto incurvo, apice uncinato, 

 intus valde ciliato. Palpi filiformes, articulo ultimo fusiformi-truucato. Mentum transversum, 

 antice profunde emarginatum et dente medio brevi bifido instructum. Ligula cornea, apice 

 truncata pilisque duobus longis aucta ; paraglossia membranaceis liberis, earn paulo superantibus. 

 Pedes robusti : tibiis masculis * (in speciebus Maderensibus) modo intermediis, modo posteri- 

 oribus plus miuusve cui-vato-dilatatis et intus ante apicem interdum ampliato-distortis : tarsis 

 anticis in maribus articulis primo, secundo et tertio dilatatis, cordatis et subtus biseriato-setosis : 

 unguiculis simplicibus. 



Both Argutor and Omaseus, although formerly located far apart, are now 

 universally allowed to be but sections of the great genus Pterostichus ; and 

 perhaps rightly so, since it must be admitted that theu- distinctive characters are 

 (like those iadeed of all the subdivisions of the latter, as now received,) so small, 

 and, being merely external ones, merge into each other by such slow and imper- 

 ceptible degrees, that it is impossible, except under a very lax system and some- 

 what unaginary laws, to regard any of them as of generic importance. Neverthe- 

 less, since it is equally true that the several subsidiary modifications into which 

 the Tterostichi have a tendency to distribute themselves are well enough defined 

 in their normal states to be made use of with much convenience, for more than 

 subsidiary purposes, in countries where the intermediate connecting links do not 

 exist, and since the few representatives of the entu-e group which I have hitherto 

 detected in the Madeka Islands belong essentially to Argutor and Omaseus as 

 formerly enunciated, I have preferred in the present instance keeping them sepa- 

 rate, — deeming this brief remark as sufficient to point out how far they have any 

 real claims for isolation when a wider system of arrangement, so as to embrace 

 the whole of then- allies kno^vn to science, is entered upon. The Madeiran species 

 of Argutor differ very materially from those of boreal and temperate climates, as 

 radiating from a larger and apterous type which appears to attain its maximum 

 in Mediterranean countries, though especially perhaps in the north of Africa, on 

 the elevated Serras of Spain and Portugal, and m the Pyi-enees. To this section 

 belong the A. Abaxoides, Amaroicles, Barbara, Hispanica, and other such-Hke 

 forms, which would abnost seem, prima facie, to merit the right of removal from 



* Species hujus generis quae insulas Maderenses colunt secundum tibiarura maris structuram hoc modo 

 apte dissolvi possimt : 



§ I. TiUce intermedin ante apicem intus valde ampUato-distortcB. 



1. Tibi» posticae ad apicem dilatatse robustus. 



2. Tibiae posticse ad apicem fere simplices dilatieollis. 



§ II. TibicB intermedicB aid simplices, aut ante apicem intus dbscurissime ampliato-distortce. 



3. Tibiae posticse ad apicem simplices gi-acilipes. 



4. Tibiae posticae ad apicem obscure dilatataj cm'tiis. 



