40. THAMNOPHIS 791 



fetal membrane. After lying quietly for a few seconds, 

 the young snake struggles, thrusts its head through the mem- 

 brane, yawns once or twice, thrusts out its tongue, and crawls 

 off, becoming at once very lively. As soon as the body 

 becomes dry, the skin is shed, exuviation often beginning 

 within 15 minutes after the young snake has been ushered 

 into the world. Occasionally the young snake is unsuc- 

 cessful in rupturing the sac, and smothers. (Ruthven.) 



These snakes are sometimes found in dry fields, but 

 seldom far from water. One usually encounters them along 

 the edges of streams, ponds or lakes, or in moist meadows. 

 Many are so aquatic as really to deserve the name "water- 

 snake." They frequently swim on or under the surface 

 of rivers and ponds, and at Buena Vista Lake I have seen 

 them in patches of tules a considerable distance from shore. 

 Their food consists largely of fishes, tadpoles, frogs and 

 toads. Occasionally insects, salamanders, worms, fledgling 

 birds (blackbirds), and very rarely small mammals and 

 snakes are eaten. A specimen of T. ordlnoldes couchii had 

 caught a six inch trout. 



Individual snakes, especially in spring, sometimes are 

 quite aggressive. On one occasion, while I was crossing a 

 small grassy pasture, three or four large Thamnophis sir- 

 tolls inf emails came toward me hissing and striking wildly 

 in the air. Their fierce attitude and combined attack evi- 

 dently were intended to frighten me away, but I was unable 

 to discover the cause of their excitement. On another trip 

 I shot a Thamnophis ordinoides couchii in a patch of tules 

 in Buena Vista Lake. This snake was nearly five feet in 

 length and the shot merely stunned it long enough for me 

 to grab the snake by the tail. It instantly recovered, tried 

 to pull away into the tules, and, finding that it could not 

 escape, turned upon me, and, with open mouth and many 

 hisses, came right into the boat. Although I knew, of 



