No. 433-] SNAKES OF SOUTHERN MICHIGAN 



in their habits, but erythrogaster (known about Olivet as the 

 "red-bellied black snake") is more often seen away from the 

 water, and several specimens were taken a rod or more from 

 the nearest stream, while sipedon is rarely seen more than a 

 few feet from water. Both are very active, and when once 

 alarmed are very shy, but erythrogaster is decidedly the more 

 wary and somewhat more rapid in its movements. Both swim 

 with speed and grace and can remain under water for some 

 time. Their food consists chiefly of frogs, toads, and fish ; no 

 other animal remains were found in the stomachs. They cap- 

 ture fish of considerable size, — a large sipedon having swallowed, 

 just previous to capture, a sucker (Catostomus) a foot in length. 

 Fish are usually, perhaps always, swallowed head first, but 

 frogs and toads are taken either way. Both sipedon and 

 erythrogaster will strike repeatedly and savagely when cornered, 

 but the bite is absolutely harmless, and though the teeth may 

 be strong enough to break the skin and draw blood, the wound 

 is practically painless and heals quickly, unless the teeth, which 

 are very small and easily torn from the jaw, remain in the 

 wound. Like all of our snakes, these water snakes have a very 

 strong odor, especially during the breeding season. This odor 

 is due to a thick fluid secreted in glands situated at the base 

 of the tail and opening to the exterior at the sides of the vent. 

 These glands are 20 mm. long, more or less, and are present in 

 both sexes, but in the male they lie above the hemipenes and 

 are therefore less easily discovered. The secretion of sipedon 

 is yellowish or brownish in color and has an odor difficult to 

 describe but very characteristic ; to me it smells slightly " burnt " 

 and is very disagreeable. The secretion of erythrogaster 'is white 

 or pale yellow and has a slightly acid, musky odor quite differ- 

 ent from that of sipedon, and, to me, not so disagreeable. Such 

 statements are obviously insufficient to enable another observer 

 to make much use of them, but it is practically impossible to 

 so describe an odor of this kind as to make it recognizable. The 

 difference between the two kinds of snake is, however, very 

 marked to any one smelling first one and then the other. 

 . Both of these water snakes are accustomed to come out of 

 the water, especially on sunny days, and lie, more or less coiled, 



