^ [J:inii;iry, 



Abdomen destitute of minute pubescence Empieurus. 



Abdomen with dense minute pubescence. 



Elytra with punctures intercalated at base between series 

 1 and the suture — 

 Elytra with numerovis raised tubercles Cyphelophorus. 



Elytra without raised tubercles — 



Pseudepipleuron broad Trichelophoras. 



Pseudepipleuron absent (or narrower than true 



epipleiiron) Meghelophorus. 



Elytra without intercalated punctures — 



Last joint of max. palpi oval Atracthelophorus. 



Last joint of max. palpi asymmeti ical Helophoms. 



As the structure of the elytron is of great importance in the 

 taxonomy of the Helophorini, and as it is not generally understood by 

 entomologists, I will now give some brief particulars about it. 



If we take off the elytron of a Helo2)horus (for example H. lati- 

 collis) and examine it carefully, we find that there are ten series of 

 punctures, the outer one of which is placed very close indeed to a raised 

 elevation ; beyond this raised elevation there exists an eleventh series 

 of punctures placed very close to the fine but raised outer margin of 

 the elytron, and on turning the wing-case on to its edge we find beyond 

 the outer margin another part covered with a very dense fine pubescence ; 

 this part is rather broad at the shoulder, and becomes backwards 

 gradually nai'rower, ceasing altogether at about one-fourth or one-fifth 

 of the length of the elytra from the tip. 



If we treat Empletirus rngosus in a similar manner, we find the 

 ten series of punctures, and outside the tenth a projecting ledge, the 

 tenth series being not close to this ledge, which is flat and shining, and 

 is limited externally by a fine margin forming the edge of the wing-case 

 as seen from above. Turning over the elytron we find the eleventh 

 series of punctures placed on a broad shining space. At first sight 

 there seems to be no band of pubescence to correspond with that so 

 conspicuous in H. laticollis, but careful examination shows this band 

 to exist in a very reduced form just behind the shoulder, and much 

 concealed by being turned inwards. 



The pubescent band in H. laticoUis is indisputably the epipleuron. 

 The distinction between the two insects we are comparing, may be 

 summed up by saying that the tenth interstice (not counting the 

 sutural interval) is in laticoUis a small insignificant raised area, placed 

 so as to look outwards ; while in rngosus the tenth interstice is a very 



