1917.] 211 



visited by me, namely, the parish of St. Merryn, near Padstow. and the 

 adjacent districts. To one who is familiar with the insects in their native 

 habitat no doubt is possible as to their distinctness specifically. 



When quite freshly caught they differ greatly in colour, li. ochraceiis is a 

 bright brown, while R. solstitiulis is quite distinctly greenish brown ; in ad- 

 dition, the former is, on the whole, a smaller insect. The difference in habita 

 is, however, quite striking and decisive, although both occur about the same 

 part of the year, namely, the middle of July. 



7?. sohtkialis is well known to the local people as the "cliff beetle." Its 

 flight is crepuscular, lasting for about an hour after sundown. In some 

 seasons the insect is extraordinarily abundant. Its favourite haunt is round 

 tlie tamarisk bushes, which are planted along the tops of all of the slate-built 

 boundary-walls of the fields and roads, especially near the coast, the j)lant 

 forming one of the characteristic features of the district. The beetles fly swiftly 

 till they meet with such a hedge and then circle round the bushes (especially 

 round the higher branches) in great numbers ; the individuals mostly do not 

 fly along the hedge lines, but in general maze, to and fro and up and down. 

 Correlated with this liking for the highest branches of the bushes is another 

 habit. The house at which I stayed this summer was at some distance from 

 others, and was the highest object in the neighbourhood. The insects flew in 

 clouds, like a swarm of bees, round the chimney-stacks and roof-ridges ; each 

 stack had many hundreds round it on a suitable evening. In their blundering 

 flight many collide with the inner edge of the chimney-pot and fall into the 

 rooms below, where they fly swiftly round ; if the windows be opened, nearly 

 all at once escape, though I have never seen any of those flying by the house 

 enter by the window. In some years the number that collect in rooms in this 

 way are sufficient to amount almost to a pest. The flight ceases as suddenly 

 as it starts ; I have some evidence that there is a second (probably smaller) 

 flight before sunrise. In the daytime most of the individuals have disappeared, 

 although a few may be found resting on the tamarisk ; if these are disturbed, 

 they may either fly off in a lumbering manner or lie where they fall to 

 the ground. 



The habits of R. ochraceiis are totally distinct. The insect appears to be 

 restricted to colonies on the cliff-borders in places where the turf has been 

 undisturbed for many years, and consists of thrift and other seaside plants 

 mingled with the grass. I originally found the species on such a cliff-edge 

 overlooking Porthcothan Bay, and it was there in fair numbers this July ; I 

 have also seen it at various Fpots between Mawgan Porth and Stepper Point, 

 notably at a point on the cliffs above Bedruthan, the cliffs between Cataclews 

 Point and Mother Iveys Bay (where I have seen several flying simultaneously), 

 and above Stepper Point. Doubtless other colonies occur on that coast. This 

 insect flies for about two hours round about midday ; its flight is a rapid mazing 

 one above and among the herbage — in fact, it flies very like a large Rombus, 

 and can readily be mistaken at a distance for one of the paler species. In these 

 places one never sees R. solstitialis. 



I am not aware of any anatomical enquiry having been carried out on the two 

 species, but, in view of the totally distinct facies and habits, I am quite sure 

 they are distinct. 



