INQUIRIES RELATIVE TO CRAAVFISH. 3 



Other Crustacea will be found parasitic upon fishes and other 

 aquatic creatures, some in their mouths, stomachs, or intestines, or 

 attached to their gills, or gill covers. Other kinds inhabit the 

 shores of bays, creeks, coves, &c., beneath rubbish, or grass, or in 

 the sand, or on the plants submerged in the waters, or even be- 

 neath stones and other matter in ponds, sometimes at great depths. 



Some attack fishes, wound them, suck their blood, or devour 

 them ; while others feed upon their eggs. 



Various kinds of fishes swallow Crustacea, and they may be 

 found in their stomachs. 



Catfishes often cram themselves with them, and with their eggs. 

 Their eggs form a dainty morsel for aquatic insects and other crea- 

 tures. 



All these creatures of whatever form or kind will be acceptable, 

 in all their stages, from the egg to the adult. They can be sent in 

 alcohol, or alive, as may be most convenient. 



When placed in fluid, their colors and markings should be noted 

 and sent at the same time as the specimens. 



On the last page of the present circular will be found the figure 

 of a crawfish with a separate representation of the tail, taken from 

 the "First Book of Zoology," by Professor E. S. Morse, (D. Apple- 

 ton & Co., New York.) 



Answers to the queries may refer merely to the number of the 

 questions. 



Full credit will be given to all who interest themselves to send 

 specimens and observations. 



JOSEPH HENRY, 

 Secretary Smithsonian Institution. 



