INTRODUCTION, XIX 
sufficient to warrant the belief. Instances reported to the writer concerned 
some known to be snake-eaters; others known to lay eggs, paying no farther 
attention to them, and others of undeterminable species noticed by incom- 
petent observers. 
The Musewm of Comparative Zodlogy possesses a specimen of Coluber 
constrictor, the “ Black Snake,” taken in Essex county, Massachusetts, by 
Prof. Putnam, the stomach of which contained a half-digested specimen 
of Cyclophis vernalis, the “Green Snake,” and another of Storeria dekayi, 
DeKay’s “Brown Snake.” It is a well established fact that this snake and 
others feed upon their own species at times. Specimens of viviparous 
species, in which the young were about ready for delivery, have led some to 
the mistaken belief that the little ones had been swallowed. 
The classification adopted in the following synopsis includes all serpents 
in four groups or suborders: ScoLECOPHIDIA, worm snakes ; ONYCHOPHIDIA, 
clawed snakes; AcAcopHipiA harmless snakes; ToxicopHIDIA, venomous 
snakes. 
ScOLECOPHIDIA. 
Those of the first suborder are subcylindrical, wormlike, burrowing 
species, which feed upon worms, larvee of insects, and the like, living 
beneath the surface of the ground. The body is usually elongate, and 
the tail short and thick. On account of their subterranean habits, the 
eyes are protected by thickened plates, and are more or less imperfectly 
developed. Probably it is by the sense of smell that the presence of food 
is detected. The mouth is comparatively small, and the bones of the skull 
are more firmly articulated than in other Ophidians. There is great simi- 
larity between the scales of the back and those of the ventral surface. 
The body is marked by a certain rigidity, necessary in burrowing, which 
makes these snakes very awkward travelers upon the surface of the ground. 
As if to aid in pushing, the tail is in cases provided with a sharp spine, 
and in others it is truncate and tubercular. Venomous Scolecophidia are 
unknown. North American representatives of the group are found in ten 
or eleven species of the family Typhlopide. They range from California 
and Texas southward and westward. Worm snakes belong to tropical 
and subtropical regions of both hemispheres. Certain species possess a 
rudimentary pelvis, 
