376 CLAVlCoKNIA. [JHmis. 



much larger number will be discovered ; six species occur in Britain, 

 which may be distinguished as follows : 



1. Thorax impressed at base, with a lateral line 

 on each side pantllel to margin, reaching from 



base to apex (Elinis, i. sp.) E. JENEDS, Mull. 



II. Thorax not impressed at base. 



i. Thorax with a lateral line on each side 

 parallel to margin. 



1. Length 3 mm.; elytra behind middle 

 wider than thorax ; lateral lines of thorax 

 somewhat converging in front (Latelmis, 



Reitter) E. VOLKMARI, Pant. 



2. L. 1 mm. ; elytra and thorax forming a 

 parallel-sided oMong; lateral lines of 



thorax parnllel (Esotus, Muls.) . . . . B. PARALLELOPIPEDUS, Miill. 

 ii. Thorax without lateral lines. 



1. Thorax finely punctured but not rugose ; 

 elytra with second and fourth interstices 

 slightly r.ised ; antennae, as a rule, darker, 



at least at apex. (Riolus, Muls.) 



A. Length 2 mm. ; elytra longer in pro- 

 portion to thorax ; colour darker . . E. SUBVIOLAOEUS, Miill. 



B. Length l-g-l mm.; elytra shorter in 



proportion to thorax ; colour lighter . E. CTTPREUS, Miill. 



2. Thorax finely rugose ; elytra with second 

 and fourth interstices quite even ; antennae 



red, not darker at apex E. NITENS, Miill. 



E. eeneus, Miill. Black, moderately shining, with the elytra of a 

 dark bronze metallic colour, clothed with very short and fine greyish 

 pubescence ; head exceedingly finely punctured, antennae brown with 

 base red ; thorax narrower than elytra, as long as broad, gradually a little 

 narrowed in front, upper surface divided into three portions by lateral 

 lines on each side of disc parallel to sides, and with a transverse im- 

 piession at base ; elytra convex, sharply narrowed behind, with strongly 

 punctured striae, fourth and sixth interstices somewhat raised ; legs pitchy- 

 brown, tarsi reddish. L. 2 mm. 



In running water, clinging to stones, &c. ; somewhat local, but by no means 

 uncommon; generally distributed in the London district and the South; not so 

 co'nmon perhaps in the Midlands, but widely distributed ; Yorkshire ; Manchester 

 and Northumberland districts; Scotland, Solway, Tweed, Forth, and Moray districts, 

 and probably general ; it is most likely as common in Ireland. 



B. Volkmari, Panz. (Latelmis Volkmari, Reitter). Ey far the 

 largest and broadest of our species, and easily recognized by its size ; 

 oblong, black, with a very slight, often almost imperceptible bronze 

 reflection ; head finely rugose, antennae of a bright reddish colour at 

 base, darker towards apex ; thorax about as long as broad, finely punc- 

 tured, slightly narrowed in front, with the engraved lateral lines slightly 

 converging towards apex, and with no impression at base ; elytra rather 

 long, rather broader at base than thorax, somewhat widened behind 



