The Lake and Brook Lampreys of New York 449 



crease in the stream would tend to cover the larvas still 

 deeper. 



Larval Life. — After the larvae leave the nest they wander 

 down the stream until some suitable place composed of sand 

 and mud is found. This suitable place is most often in the 

 concavity of the stream where the water flows slowly and 

 there is not great danger of being washed away by every 

 freshet. Judging from specimens in the laboratory that were 

 placed in glass vessels with water, and sand from the native 

 habitat, each larva has a canal or burrow of its own. This 

 burrow usually opens on the surface of the sand. In this 

 burrow the larva remains, changing its position at will and 

 also making a new burrow with a new surface opening as in- 

 clination or necessity demands. In those observed in a glass 

 vessel where there could be no doubt, the canal was curved, 

 the convexity of the curve being downward (PL VIII, fig. 

 4q). The larva was curved correspondingly ; but the dorsal 

 side was always up as shown in the drawing. Often in mov- 

 ing to and fro in the canal the tail would be higher than the 

 head. If disturbed the larva leaves the burrow and worms 

 itself through the sand with great alacrity. They do not leave 

 the protection of the sand if they can possibly avoid it. In 

 their natural home beside the streams, they are usually onlj^ a 

 few centimeters under the surface of the sand and frequently 

 not more than 15 to 40 centimeters below the water level. In 

 taking them the sand is shoveled up from the stream and car- 

 ried out to the shore and placed on the bank or upon some- 

 thing else so that the water may drain away. As soon as the 

 sand is prettj' well drained, any larvae present wriggle out to 

 the surface where they can be seen. To obtain the smaller 

 ones it is necessary to take somewhat more care and spread the 

 sand out in a thin layer ; sometimes also it is advantageous to 

 pour water over it. 



The way in which the larvae enter the sand from the water 

 and the way they move around in the sand was very easily 

 and satisfactorily demonstrated b}' placing some of the sand 

 from the native habitat in a glass dish and partly filling it 

 with water. The sand was washed to avoid turbidity then a 



