538 Coleopterological Notices, V. 



HISTER Linne. 



In this geDus I find a remarkable and puzzling inconstancy in a 

 structural character, which ought apparently to be a very good one — 

 the emargination of the prosternal lobe. For example in two other- 

 wise completely similar specimens of depurator before me, both 

 bearing the same label, the lobe is broadly subtruncate at apex, 

 with the angles broadly and continuously rounded in one, while in 

 the other it is visibly emarginate, with the angles acute, prominent 

 and dentiform. Possibly these differences may be sexual, but until 

 their origin is determined it will be unsafe to separate species upon 

 them, unless sustained by decided divergencies in other parts of the 

 body.^ 



In Hister the elytra have nine striae, besides the one or two sulci 

 of the inflexed flanks, but several are more or less abbreviated or 

 radically modified, so that the apparent number is much less. The 

 first two from the suture are generally greatly abbreviated in front, 

 the next four usually more or less nearly entire, the seventh is fre- 

 quently represented by an obsolete subapical line of punctures which 

 is rarely striiform,^ the eighth by the outer subhumeral stria, some- 

 times obsolete or otherwise modified, and the ninth by a series of 

 small, distantly spaced punctures along the crest of the lateral con- 

 vexity. If this sequence be borne in mind, it will always be easy 

 to understand the detached striae and series of punctures met with 

 in the various species. For instance in abbreviatiis, the basal part 

 of the coarse lateral stria is a basal remnant of the outer subhumeral, 

 the apical part being the inner subhumeral. Besides the oblique 

 humeral stria, there is in most species a short subtransverse outer 

 humeral ; it is impossible to state the exact significance of either of 



1 Since this was written I have examined good series of depurator and incertus 

 and find that of nine specimens of the former, seven have the prosternum 

 emarginate, and two broadly rounded. Of twelve examples of mcertus, six 

 have the prosternal lobe narrowly and evenly rounded, four broadly subtrun- 

 cate with rounded angles, and two emarginate with acute angles. 



2 The oblique inner humeral is certainly not the basal part of this inner 

 suhhumeral as stated by Dr. Horn (Proc. Am. Phil. Soc, XIII, p. 287), the 

 true base of the latter being sometimes seen as a short stria near the base of 

 the former, as remarked under Epierus cornutus. In Psiloscelis repleta Lee, 

 the inner subhumeral is entire and similar to the first dorsal ; it crosses the 

 oblique humeral stria near its middle point and attains the hasal margin, the 

 striae not being at all distorted at the point of crossing. 



