HARRIS : CRAYFISHES GENUS CAMBARUS. 93 



connection with the river. The animals were generally found 

 out of the water, just within the hole, and upon being alarmed 

 would dron down. Having no chance to escape, "they were 

 quite savage." 



He believes that too much water is "disagreeable" to the 

 animal, and that the "mounds," above and away from the 

 streams, are the result of an attempt of the animal to obtain a 

 location where he can safely remain in or out of the water. 

 Since crawling out on an open bank would expose them to many 

 dangers, they burrow in the saturated soil, "and at times 

 penetrating from the stream bed." An opening is usually left 

 on the side or at the top. The "mounds," he concludes, are 

 usually built when the streams rise, the animals leaving the 

 swift current and taking to higher ground for safety. 



Mr. Holder was informed by a gentleman residing in Free- 

 port that not many months before heavy rains had so greatly 

 increased the volume of the little river that many quite large 

 trees were almost submerged. When the water was at its 

 height it was noticed that above water the trunks were com- 

 pletely covered with crayfish, which crawled up out of the 

 water by hundreds, covering every available space. 



He states that in certain portions of the Western country the 

 work of the crayfish often greatly increases the difficulty of 

 breaking up new land. Some farmers, however, consider that 

 they enrich the land by keeping it open and in many other 

 ways, and that land with the "crayfish heaps" is worth more 

 per acre from this cause. 



Hargett ["dO) gives observations on the crayfish in the region 

 around Oxford, Ohio. He mentions C. gracilis and C. ohesus, 

 and his observations probably apply, for the most part at least, 

 to these species, although some may apply to a third form. He 

 found them abounding in the streams of the adjacent country, 

 where they might be observed at any time during at least eight 

 months of the year, leaving the winter quarters at first sight of 

 spring, and returning only with freezing weather in the autumn. 



According to him, the best time for taking the "larger species 

 of Cambarus, such as gracilis, obesus, etc.," was just at the 

 spring thaw, especially during the usually accompanying period 

 of large rainfall, when they "venture boldly forth" from their 

 hibernating places "in the banks and fields adjoining sluggish 



