ORTMANN: THE CRAWFISHES OF THE STATE OF PENNSYLVANIA 345 
Practical experience gradually revealed to the! writer the best method of col- 
lecting crawfishes. At first the writer was rather inexperienced, and did not know 
where to look for certain species. But the necessary knowledge and skill were soon 
acquired. 
To collect the species living in streams, rivers, and ponds requires no special 
effort ; it is only necessary to wade into the water-course to be investigated, or to 
walk along its edge, and to discover the hiding-places of the crawfishes, which is 
done by turning over stones. <A pair of rubber-boots, or wading-stockings, pro- 
tected by ordinary bathing-shoes, is very convenient; and also a small landing-net, 
the bag made of minnow-netting. Frequently specimens may be caught with the 
hand. In certain places, and in the case of certain species (Cambarus limosus) water- 
weeds often furnish hiding-places, and here it is advisable to use a larger landing- 
net with a long handle, which is pulled or pushed through the weeds. 
More work is required in collecting the burrowing species. ‘The first thing is to 
locate them, which is generally done by searching for the mud-chimneys built over 
their burrows. But it is not always easy to find these, particularly in late summer 
and autumn, the chimneys being then rather inconspicuous. I generally first ascer- 
tain favorable localities, such as swampy places in the bottom-lands, and springy 
places on the hillsides. It is a very good plan to closely watch ditches by the road- 
sides. Here the chimneys generally are easily detected, and in the neighborhood 
of such places large colonies often may be found. After a burrowing form has been 
located, the most difficult work begins, for the inhabitant of the burrow must be 
dug out of its hiding-place. Care must be taken while digging not to injure 
the crawfish. Sometimes the work can be done with the bare hand, but only in 
those rare instances in which the burrows are in very soft ground. Generally the 
work must be done with pick and shovel, but, as it is inconvenient to carry these 
cumbersome tools along on an excursion and a gardener’s trowel is a little too weak, 
I have found a pioneer’s bayonet, such as is used in the United States Army, to be 
a tool which beautifully serves the purpose. These bayonets may be had in gun- 
and ammunition-stores in the larger cities, and are practically indestructible. 
After locating a crawfish-hole, I begin to dig down around it, loosening the 
dirt with the bayonet, and removing it with my. hands, always taking care not to 
lose trace of the hole. Generally it is necessary to'go down upon the knees (rubber 
boots are useful here), and even the belly, in order to reach the bottom of the hole, 
to which the crawfish usually retreats when disturbed. Often, however, it retires 
to a side branch, in which case it is not necessary to dig so deep. As soon as it is 
felt beginning to pinch with its claws, it isa sure sign that the crawfish has been 
