TRIGONOCEPHALUS CONTORTRIX. 41 



inches; circumference of the neck, 1 inch 10 lines. In the individual described, 

 there were 150 abdominal plates, 42 sub-caudal, and four pairs of bifid plates or 

 scales near the apex. 



Habits. The Trigonocephalus chooses dark and shady places for its residence 

 in general, though at times it is found in meadows of high grass. Its usual food 

 seems to be small birds and field mice, which I have more than once found in its 

 stomach. In confinement it could never be made to take any food; though 

 different small animals were oftered, it would kill but never eat them. 



Geographical Distribution. The Trigonocephalus contortrix has an extended 

 geographical range. I have received it from the western parts of New England 

 to middle Florida inclusive, and from the shores of the Atlantic to the borders 

 of the Alleghany mountains. As yet, I have no evidence of its existence in 

 the valley of the Mississippi; its place is there probably supplied by the 

 Toxicophis (Trigonocephalus) atro-fuscus of Troost, to which its habits are very 

 similar. 



General Remarks. This animal was first described by Linnaeus, in the 

 twelfth edition of his Systema Naturae, under the name Boa contortrix, and it 

 ranges well under his genus Boa, which included those serpents, venomous or not, 

 that had plates under the tail, as well as on the abdomen. The specimen from 

 which he took his description, was sent him by Dr. Garden, and had, according 

 to his account, the same number of plates as the animal here described, though 

 he does not mention the two or three scales or bifid plates on the tail. He says 

 furthermore, that he found the gland or sac for containing the venom, but that 

 there were no fangs, which might have been the result of accident, as the larger 

 fall out and are succeeded by others. It cannot be imagined why he should have 

 given a reference to the Hog Nose of Catesby,* especially as this is far removed 

 from his genus Boa, in having scales or bifid plates under the tail. The 



* Gates., Carol., &c., vol. ii. pi. Ivi. 

 Vol. III.— 6 



