202 [July. 



the interstices broad, and flat, the 2nd, 4th, and 6th slightly convex : 

 there is little punctuation on the interstices and a minute and scanty- 

 hairiness that is difficult to detect. 



The species is common tliroughout Central and Northern Europe, 

 but I liave no evidence of its occurrence in the South : records of such 

 may be found, but I suspect they all refer to closely allied forms. 

 It (under the synonymic name grandis) is recorded by Motsehoulsky 

 as occurring in East Siberia, whether correctly I do not know. 



1. — Meghelophoms aeqiialis, Thoms. 



Closely allied to aquaticus, but on the average considerably 

 smaller (length, h\-& mm.), with the sculptiu'e of the head and thorax 

 much less coarse and the colour of these ^ usually more brilliantly 

 metallic. The teeth on the hind-inargiu of the last ventral plate are 

 extremely short. 



M. aequalis is a very variable species, and being very closely 

 allied to aquaticus may, as many believe, be proved to be not really 

 distinct. When the variations of aequalis are examined it is, however, 

 seen that there are but very few specimens that cannot be easily 

 distinguished from aquatimis. The two forms live in intimate associa- 

 tion here, and I have not been able to establish any difference in the 

 aedeagus as constant, though I have examined it in many specimens ; 

 the more slender form of the organ in aeqtiaiis being the natural 

 accompaniment of the smaller size and less robust build of the 

 whole insect. 



Varieties of slender, parallel form, with the thorax black in the 

 middle, have been found at an elevation of 4-6000 ft. in the Tyrol by 

 Champion (Campiglio and the Mendel Pass) ; and a similar, though 

 not so strongly marked, variety was found by me at a similar elevation 

 at Mont Louis, Eastern Pyrenees. These dark, slender specimens are 

 of interest in connection with H. frigidus Graells. 



Dark specimens have the elytra much infuscate, but often in 

 an irregular manner so as to leave pale spots or areas. 



A variety from Germany with this pale spotting, and with the 

 thorax a little more sinuate at the sides than usual, was sent me by 

 the late Herr Wehncke as " splendens n. sp.," but no description has 

 been published, though the form is worthy of a name. There is 

 another example of splendens from Germany (Maerkel) in the British 

 Museum collection. 



