20 Mr. F. P. Pascoe on some new or little-hnoimi 



subtriangular, gi-adually enlarging to the ninth, which, with the tenth 

 and eleventh, are of equal thickness, the latter a little pointed at 

 the apex; eyes prominent; mentum transverse, narrowed in front, 

 its anterior angles produced; labium slightly emarginate ; maxillary 

 lobes narrow, nearly equal in size, fringed with long hairs, the inner 

 lobe with a strong hook at its external angle ; palpi rather short, 

 the terminal joint of the mas:illary subcylindric, of the labial ovate; 

 mandibles bifid at the apex, with a slender tooth internally ; prothorax 

 twice as long as the head, sparingly punctured, a small process at the 

 anterior angle, posteriorly a little contracted, and at the base a curved 

 impressed line ; scutellimi broadly triangular, the sides rounded ; elytra 

 about twice as long as the prothorax, punctate-striate, slightly concave 

 between the suture and the external border^ where they bend down 

 almost at a right angle ; coxae not approximate ; femom long, robust ; 

 tibiae short, slightly curved, subtrigonate, the posterior near the ex- 

 tremity finely toothed at its inner edge ; tarsi very short, the three 

 basal joints dilated, the fom'th minute, the claw-joint small, not longer 

 than either of the three basal ; body beneath dark brown, finely pimc- 

 tured. Length 3 lines. 



The insect is much narrower than I have represented in the 

 figure. 



AcHTHOsus [Tenebrionidee]. 



Caput exsertum, clypeo producto. Antennce subclavatae, articulis 5-7 

 ultimis perfoliatis, transversis. Maxillm lobo interiore hamato. Tihice 

 anticcB trigonatse, extrorsum dentatse. Corpus subcylindricum. 



This genus differs in a few points only from Antimachus, some 

 species of which it closely resembles, except that it is more cylin- 

 drical, but from which it will be at once distinguished by the 

 strongly serrated external margin of the fore-tibiae. There are also 

 remarkable differences in the mentum and labium of the species 

 described below, and in the same parts of a species of Antimachus 

 (probably A. furcifer, Gistl) which I examined for the purpose of 

 comparison. But two other species, which I refer also to Achthosus, 

 appear to have the more or less subcordate mentum of Antimaclms, 

 and therefore I have not referred to this organ in the characters of the 

 genus. So far as my limited experience goes, it appears to me that 

 the parts of the mouth are subject to the same variations as other 

 organs, and, except certain differences of plan, which, however, are 

 rather characteristic of higher groups than genera, the variation in 

 form or outline of these organs is generally only one of degree. I 

 believe that they are supposed to be more constant in their cha- 

 racters because they are seldom examined, and that one species is, 

 as a matter of course, taken as the type of the rest. For this reason 



