(Page 514) 

 punctation, the surface not shagreened; abdomen more finely marginated, 

 with all over, but especially posteriorly more robust punctation. L. 

 4.5-5 mm. ('ig. 149). 



In the & the hind tibiae are feebly undulated, and on inner side 

 at tip with a small, yet distinct spine; abdominal third and fourth 

 ventral joints are posteriorly slightly depressed and feebly emargi- 

 nated, the fifth hardly feebly depressed, the sixth deeply incised. - 

 In the Q the sixth ventral joint is obtuse angularly prolonged. 



In like places as pubescens , distributed like this .and common in 

 this country. The larva and puppa are found in the stem of common water 

 mustard ( Brachyolobus amphibium ) and reared by Hr. Laerer I. P. Kryger 

 (7. 8. 1912). He presumes that the larva here lives on small snout- 

 beetle larvae ( Poopha^us sisymbrli ), which were found to be numerous 

 in the stems, and he observed at the rearing, that it by the assistance 

 of the anal joint, which serves as support- and pushing-joint and ends 

 in sucking-discs, was able to crawl up at a leaf surface in a measuring 

 manner, and could adhere to a glass plane, but however not crawl up at 

 same. The larva pupates in the plant stem in a double cocoon, and de- 

 velops in the course of some weeks into beetle. - It is likely that the 

 closely allied species: Stenus pubescens and pallitarsis et. al. live 

 and develop in a similar manner as binotatus . - Dr. "'esenberg-Lund has 

 observed that these Stenus species with broad tarsal joints and water- 

 shedding hair-vestiture not only mounts the water plants, but also run 

 upon the water surface, and in a most peculiar manner and with astonish- 



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