BY REV. T. BLACKBURN. 485 



It must be remembered, however, that this character is only 

 reliable in mature specimens, immature examples often having 

 their elytra so shrunk and distorted that it is impossible to deter- 

 mine whether they have or have not systematic inequalities. In 

 such specimens, however, the ingequalities are usually different on 

 the two elytra. 



The species with symmetrical elytral series and elytra devoid 

 of lateral inequalities fall into two sections fairly reliably to be 

 distinguished (immature specimens and those very long immersed 

 in spirits excepted) by the sculpture of the elytra. In one of 

 these sections the elytral series are invariably fine, close, and 

 extremely symmetrical, with interstices usually quite flat and very 

 fine striaj if any; while in the other section the elytral sculpture is 

 variable, the series in most of the species being considerably 

 coarser and in very few species perfectly symmetrical throughout 

 (some of the discal series being more or less zigzagged in places and 

 the 10th seriesnear the base being almost invariably much confused), 

 the strite when present distinctly less fine and less scratch-like, 

 the interstices in many examples decidedly convex. Each of 

 these sections moreover has its own type of prothoracic sculpture 

 vaiying somewhat in degree (owing probably to length of immersion 

 in spirits, age of specimen when killed, &c.), but after a little 

 practice easily recognisable. In the species of the former section 

 the disc of the prothorax is (normally) finely and closely punctu- 

 late and not or scarcely asperate; while in the latter the disc is 

 either very sparsely punctured or strongly rugulose. 



So far it is not difficult to go with moderate confidence in deal- 

 ing with these most perplexing insects, but when one comes to 

 di\ ide into species the specimens pertaining to each section, the 

 task is almost hopeless. It is a difficult matter to find two 

 specimens that can be confidently asserted (apart from the circum- 

 stances of capture) to be identical, and it frequently happens that 

 two specimens which one knows to be conspecific dry into the 

 appearance of belonging to two species. I am of opinion that 

 the determination of the species is impossible, except by the means 

 of some student with plenty of leisure time at his command 



