Occasional Papers of the Museum of Zoology 1 1 



Thyanta custator i *Stcnopoda culiciforviis 



Acrostcmum hilare 5 *RedHvhis pcrsonatus 



*Rhacognathus aniericaiius ... I Nobis ferns 



*PcriUus bioculatns 2 Lygus pratensis obliiicatus. . . . 



*P. b. claudus I *Lopidea ccvsar 



Apateticus bracteatus 3 Gerris margumtus 3 



A. cynicus ll Gerris rufoscutellatus 5 



Podisus maculiventris 7 *Notonecta irrorcia 2 



*Oncopeltus fasciatus 3 Ranatra atncricaiia i 



*Lyg(eus furcicus i *Bcnacus griseus 7 



Lygceus kalmii angnstomargi- Lcthocerns sp 2 



natus 4 Bclostoma flnniineum 6 



*Gclastocoris sp i 



After considering carefully the nature of the drift material, 

 the physiography of the region, and the correlation between 

 weather conditions and the extent of the drift, I came to the 

 conclusions that most of the insects which were washed ashore 

 near my camp, west of Bridgman, came from the region w^est 

 of Stevensville, six or seven miles to the north ; that the insects 

 had flown far out over the lake, had fallen in, and had been 

 slowly washed in onto our shore ; and that only the larger, 

 more heavily chitinized forms had endured their long immer- 

 sion and the heavy pounding of the surf. The drift was neg- 

 ligible at the Saw^yer Dunes when the wind was from the 

 southwest, and reached its maximum w'hen a bright, compara- 

 tively calm morning was followed by an afternoon with a 

 strong northwest w'ind. The marshy lakes near Stevensville, 

 which are known as the Grand Marais, are the only suitable 

 habitats near the Sawyer Dunes for the Belostomatidae and 

 the larger water beetles, and the only probable habitats for 

 such Orthoptera as Mecostethus Uneatus — all of which were 

 found commonly on our beach. And the dunes are much 

 lower and narrower in the Grand Marais region than they are 

 farther south, and thus present less of a barrier to insects of 

 the region behind the dunes. It is noteworthy that only two 



