494 MEMOIRS OF THE CARNEGIE MUSEUM 



highly esteemed European forms, but I know from my own experience that, as 

 regards quality, the former are not inferior to the latter. Young specimens (and 

 chiefly soft shells) may be fried in butter and eaten shell and all, while the abdom- 

 inal muscles of older ones, when boiled in water, are very good. 



Of course, it is hard to create a taste for crawfishes among the mas.ses, Imt I do 

 believe that it would be worth while to try. Crawfishes are so abundant in certain 

 parts of the larger rivers, C. limosus in the Delaware, and C. ohscurns in the Ohio 

 drainage, that it is easy to get an}^ amount of them. It also would not be difficult 

 to raise them, for instance in ponds, and to supply the market regularly and judi- 

 ciously. And further, I do not see, why the "tails'' (abdomen) could not be used 

 for canning, exactly like the tails of shrimps and prawns. 



Beyond this, crawfishes are used only as bait by fishermen. This use is quite 

 general, and crawfishes form an important part of the fisherman's outfit especially in 

 western Pennsylvania. They are most valuable in fishing for Black Bass {Microp- 

 terus), since these fishes seem to be very partial to this l)ait. 



3. Crawfishes as scavengers. Their food. Their enemies. 

 The indirect economic value of crawfishes is best expressed by saying that they are 

 scavengers, as decapod crustaceans in general. They dispose effectively and quicklj^ 

 of any decayed matter, animal or vegetable, coming within their reach. They also 

 eat living creatures. This was known previously. Abbott (1873, p. 83) calls them 

 (C limosus and hartuni) "omnivorous," and "scavengers," and says that they eat 

 water-weeds, and seize young Cyprinoid fishes. Andrews (1904, p. 175) fed C. 

 limostis in the laboratorv on raw and cooked meat, raw eggs, pieces of earthworms, 

 and on Chara and Hi/drodictijon. Williamson (1901, p. 12) reports that ('. laonon- 

 galeyisis was caught in traps baited with raisin and oatmeal. I used for my speci- 

 mens in the laboratory all kinds of meat, and since I am especially fond of smoked 

 sausage, I let them often partake of it when I had it for lunch. They also eat earth- 

 worms and green vegetable matter, for instance seedlings of several weeds (Galin- 

 soga, and Rumex acetoseUa), grass, and water- weeds ( ValUsneno). In nature they are 

 often found at carcasses and other animal refuse lying in the water. They eat in- 

 sects. For instance I have seen C. hartonl taking grasshoppers used as bait while 

 fishing for trout (Tub Mill Run, Ross Furnace, Westmoreland County). In the 

 case of the chimney-builders vegetable matter seems to be largely resorted to, not 

 only fresh plants, but also decaying vegetation being used. In digging them out of 

 their holes I repeatedly found masses of decaying leaves and the like lodged in some 

 side branch of the hole in such a position that they could not have fallen in acci- 



