THE CANADIAN ENTOMOLOGIST 173 



also Rybiosoma hifariiis Kby. They are all also taken by dredging 

 in muddy, weedy situations. 



So far, I have never succeeded in finding any of our species 

 of Agabus at all commonly in their real homes. One spring 

 se\"eral species were quite plentiful in ditches connecting with the 

 streams running into the Red River. The water was very high, 

 and apparently beetles which had passed the winter in the river 

 were on their way, together with a number of fish, to find a suitable 

 summer resort. At any rate, many of these slow-running ditches 

 were swarming with beetles. I took several hundreds, most of 

 which went to Mr. Roberts. 



Of Rhantiis we take notatus Fab. commonly both at electric 

 light and in muddy ponds; bistriakis Bergst. and tostus Lee. are 

 much less frequently met with. Binotatus Harr. has been taken 

 by Mr. Criddle, who also records Colymbetes strigatus Lee. The 

 common Colymbetes with me is sculptilis Harr., which often swarms 

 at electric light. Mr. Roberts tells me that rugipennis Sharp, is 

 a good species, and divided mine for me, but L don't know just on 

 what characters, and my eye is not sufficiently trained at present 

 to detect the differences. 



Dytiscus is fairly well represented in Manitoba, as we certainly 

 take six species. Circiimcinctus Ahr. easily distinguished by the 

 vellow circle around its eyes, is our commonest species, with 

 sublimbatus Lee. running it pretty close. Both come to light in 

 thousands. Fasciventris Say., hybridiis Aube., dauricus Gebl. and 

 harrisii Kby. are all rather rare, especially the two former. An 

 interesting point about our dauricus is that the specimens taken 

 in Winnipeg at light all are small, while several taken at Winnipeg 

 Beach, fifty miles away, are nearly double the size. Possibly the 

 larvae of Winnipeg specimens live in the Red River and fail to secure 

 sufficient food. 



Our rarest Graphoderes is liberus Say. and fasciatocoUis Harr. 

 is almost equally so. We take perplexus and elatiis Sharp, more 

 frequently than fasciatocoUis. I believe Mr. Roberts considers 

 these all good species, and indeed even I could separate them! 

 Our commonest species is occidentalis Horn., which comes freely 

 to the lights. It is also by no means uncommon in weedy ponds. 



