129 



was one boy in the group who was inexpressibly afraid of such 

 creatures, and to tease him the boys threw it at him. It wrapped 

 itself around the neck of the timid boy, while he fell to the ground 

 in a faint. It was regarded for a moment as a great joke, but as 

 the boy did not recover readily it became more serious. That boy 

 is to-day a raving maniac in one of the insane asylums of Pennsyl- 

 vania. He was at one time a bright and happy boy, and had it not 

 been for the thoughtlessness of his companions he might have been 

 to-day a most useful citizen instead of a man with dethroned reason. 



KEY TO PENNSYLVANIA FAMILIES OF THE ORDER OPHIDIA. 



A. No pit between the eye and nostril; pupil of eye circular; no erectile fang 

 nor poison gland in upper jaw; plates under tail divided by a middle line; 

 body generally slender and tail long. Family 1. Colubridse. Colubrine or 

 Constricting Snakes. 



AA. Pit between the eye and nostril; pupil of eye vertically elliptical; erectile 

 fangs with poison glands in each upper jaw; plates under tail (urosteges) 

 not divided by line, but extending clear across; body always heavy and 

 tail always short. Family 2. Crotalidse. The Rattle Snakes and Copper- 

 heads. (Page 185.) 



Family 1. C'olahr'dcE. Tne Colubrine cr Constricting Snakes. 



This is the family to which all serpents of this State belong except 

 the Rattle Snake and the Coi>perhead, which belong to the CrotalidiBo 

 (Page 175). The Colubrine Serpents, or members of this Family, can 

 be known hy (a) entire absence of the perforated fangs, (b) only solid 

 teeth present in the upper jaw, (c) no poison or poison glands, (d) the 

 subcaudal plates (urosteges) arranged in pairs by being divided along 

 the middle line under the tail by a line or suture, (e) no pit between 

 the eye or nostril, (f) the pupil of the eye always circular in shape, 

 and (g) the tail always as large as the length of the body. 



They do not all attack their prey by constricting or squeezing, 

 but all the constrictors belong here. It is a large family, with over 

 TOO known species, found in nearly all parts of the world. There 

 are about 21 species of this family to be found in this State. Some 

 of them are oviparous, and some ovoviviparous, or bear young 

 nourished by a yolk enclosed in a thin membrane. The habits of 

 each will be discussed in turn under its own specific name. 



KEY TO THE SPECIES OF COLUBRID^ OR COLUBRINE SNAKES IN 



PENNSYLVANIA. 



(a). SYSTEMATIC STRUCTURAL KEY. 



1. Head not distinct from body, which iscylindrical and rather rigid. 2. 

 Head more or less distinct from body, w'hich is not especially rigid. 3. 



2. Scales in 13 rows; Nasal single. No.l. Coiphophiopn anue7ius (^Say) . Page 133. 

 Scales in 15 rows; Nasals two. No. 2. Vimhiin ratciicv (B. & G.) Plate XV. 



3. Rostral plate normal, not recurved nor keeled. 4. 



Rostral plate long, upturned. No. 21. Hcteiodon platii]ii)ius (Latr.) Page ISO 



9 



