OF WASHINGTON, VOLUME XIII, 19H. 63 



reaching the creek, where I would have but five hours' time 

 at most to spend, I decided to begin my search on the gravel 

 bars of the creek, as it occurred to me that the beetle might 

 be an ordinary gravel-bar insect like Patrobus calif ornicus. 

 This was really a reflection upon the collecting ability of 

 "Bug" Johnson, and proved an unfortunate digression on my 

 part. As it happened, the first pebble I turned over concealed 

 a P. johnsoni. Immediately I had visions of collecting a 

 quart or so. Of course, I searched at once for the mate of 

 my specimen and immediately found it, but alas of another 

 very common species. During the next fifteen minutes I 

 scratched over every inch of that gravel bar, without success. 

 Then I searched the adjacent woods in every sort of place I 

 could imagine a Plerostichus to live but no luck. During 

 the next two hours I trudged up the creek, scratching the 

 gravel on every bar, looking under drift of various sorts, un- 

 der the bark of logs in the creek, in wet moss, and in general 

 defacing the landscape. It was now after noon ana half of 

 my five hours were gone. I estimated I was still a mile from 

 the falls, so I went into the woods back from the creek, where 

 the valley was less difficult, and tramped for half an hour, 

 when I reached my objective point. 



The beetles I was told would be found on the moss in the 

 spray. The spray was there and the moss, but no beetles; 

 and when I got through there was no moss left. Just before 

 leaving the falls I espied a little patch of gravel in between 

 the logs of drift and here I found my second P. johnsoni. 

 Three hours of hard work and two beetles! I was discouraged 

 and started back, following the creek. On a particularly 

 promising gravel bar I found two more specimens total four. 

 But the next half hour's work of scratching gravel gave no 

 further results, and I decided to quit. In trudging through 

 the woods I tried to solve the difficulty, wondering whether 

 the beetles really were very rare like certain species of Cyc/irns, 

 or whether I had not found their real habitat. Professor 

 Johnson said he found his specimens on the wet mossy rocks 

 while fishing up the creek. I thought it might have been a 

 dull day and the beetles, therefore, out hunting, while on a 

 bright day they would hide. With this idea I again went to 

 the creek and reached it at the spot where Professor Johnson 

 described it as impassable and with the bed filled with large, 

 mossy boulders. If my theory was correct I should find the 

 beetles hiding near the mossy rocks as my previous work 

 proved they did not hide in the moss. Such a place I found 

 in a little patch of gravel not a foot square between two large, 

 mossy boulders and there I found a pair of P. johnsoni in 



