Occasional Papers of the Museum oj Zoology 3 



worked intensively, from MacTaggert Creek (Mason County), 

 which is between the north and south forks of the Skokomish, 

 eight miles below Lake Cushman, to the creeks on Mount Steel 

 (Jefferson County), twenty-five miles above, and from an elevation 

 of 400 to 4,500 feet. 



The apparent rareness of the species may be accounted for by 

 the fact that so little has been known about its habitat. As noted 

 above, the only specimens reported upon have been found in the 

 open. Only six specimens in the series of over a hundred which 

 were acquired this summer were found on the banks of the streams, 

 and only two were farther away from the water. One found them 

 only by working slowly upstream and turning over every movable 

 stone. Usually they either floated down the stream with the 

 debris which was released when the stone under which they were 

 resting was overtiirned, in which case it took quick action to catch 

 them before they were out of sight, or they made no effort to move, 

 and in the shifting lights and shadows their color so closely resem- 

 bled a bit of fir bark or the small red stones which were abundant 

 in the streams that they were distinguished with difficulty. Occa- 

 sionally they were alert and slipped away like a shadow. When 

 placed on land they were awkward and stupid in action and 

 appearance and made little effort to escape. They were solitary; 

 never more than one was found under a single stone and indi\dduals 

 were usually well separated in the stream. There was a decided 

 element of chance to be reckoned with in collecting them, although 

 they were not uncommon. A day's collecting, six to eight hours, 

 seldom yielded more than five ; on July 30 twenty-five were found 

 in MacTaggert Creek in not more than three hours' work, while 

 a week later our day's catch from the same creek numbered only 

 four. 



Specimens were found only in streams with densely forested 

 banks with one exception; this was a little snow-fed creek on 

 Mount Steel (4,500 feet) that ran through a small alpine meadow. 



