1875.] 17 [Putnam. 



meat, it feels with its antennas for a while, and then takes the morsel 

 in its claws and conveys it to its mouth. I have twice seen the meat 

 dropped as it was passed along the base of the antennas, as if the 

 sense of smell, or more delicate organs of touch seated at that point, 

 were again the cause of alarming the animal. When the jaws once 

 begin to work, the piece of meat, or bread, if very small, is devoured, 

 but if a little too large only a few bites are taken and the food is 

 dropped and not again touched though the animal then crawls over 

 it and rests upon it without being in the least concerned. These 

 actions are best noticed by feeding with raw liver, and by not dis- 

 turbing the crawfish for some days before. When bread is offered, the 

 crawfish hardly has time to go through all his manoeuvres before the 

 bread becomes saturated and mixed with the water in small particles, 

 some of which are eaten, but the most of them are left. If food is 

 often presented, the crawfish, becoming accustomed to the disturbance, 

 and probably to the smell, pays no attention to it. 



The smallest of my living C. Bartonii cast its skin about February 

 20, but I had not noticed it for several days, and when observed it 

 was engaged in eating its old skin, and had devoured about one half 

 of it. The only observation made in this case was on the color of 

 the animal. This little specimen was, when collected, of a light 

 brown color, mottled with a darker shade; these markings are the 

 same in its new skin, and, apparently, the animal has not increased 

 in size. On January 29, it was noticed that one of the medium sized 

 blind crawfish had left its old skin and seemed to be better provided 

 with legs than before, as it had formerly suffered severely from being 

 confined in the same jar with others. Indeed, about one half of my 

 specimens were mutilated to a great extent by the terrible battles 

 which they had with each other during the journey, when I was 

 compelled to keep several in one jar, though they were in part pro- 

 tected from each other's fury by hiding under the moss placed in the 

 jar for this purpose. This specimen was carefully observed , and a 

 comparison made between its old and new skins. This individual 

 was milk white when captured, and on coming out of its old skin it 

 was of the same color, so that the theory that the grayish specimens 

 are those that have recently shed their skins will not hold good. 



The question now is, is color once attained by these animals ever 

 lost or changed by their future growth? I have now, April 23, a 

 living gray specimen with white tips to several of its claws, but as yet 



PEOCEEDENGS B. S. N. H. — VOL. XVIII. 2 AUGUST, 1875. 



