2 INQUIRIES RELATIVE TO CRAWFISU. 



while it will not do so in others. At one season of the year it will 

 wander over a wide range of surface, and at another it will remain 

 confined within narrow limits. 



Distinct species live in the mountain streams and in the springs 

 at their sources. Some frequent the marshes of the lowlands, (both 

 the fresh and salt marshes) either near the streams, or adjacent to 

 the bays, sounds, or ocean. Some occur beneath stones in rivers, 

 creeks, or branches ; iu the muddy basins ; beneath stones in the 

 rapids ; among grass and weeds in more quiet places, and in coves ; 

 under shelving grassy banks ; iu holes at the bottom of ponds, lakes, 

 dams, and mill-races. Others bore holes in the meadows, or even 

 in the hill-tops near water ; and iu bringing up the mud and clay 

 from their tube-like holes, pile it as a chimney at the entrance. 

 These species at particular times place a plug of clay in the orifice 

 of the chimney and seal themselves in for a certain length of time. 



Still others reside in the drains and mud of the rice fields and 

 plantations of the south, and sometimes burrow through the em- 

 bankments allowing the water to flood the region. 



In order to secure a more full and accurate knowledge of these 

 creatures, the Smithsonian Institution respectfully requests replies, 

 as far as possible, to the following queries. A reference to the num- 

 ber will sufiice in cases when it is inconvenient to write at greater 

 length. 



There arc three great groups of Crawfish which may be distin- 

 guished by the difference in the shajoe of the front end of the head. 



1. The first has the tip of the head with acute spine, and farther 

 back with another sharp, long spine each side.' 



2. The second has the tip of the head acutely triangular, and 

 usually with a minute tooth or notch each side just back of it. 



3. The third has the tip of the head almost conical, with the 

 sides a little rounded, or with the extreme tip armed with a short 

 tooth. 



