(30 HETERODON SIMUS. 



This serpent, it would seem, was first admitted into the tenth edition of the 

 Systema Naturce as the Coluber constrictor, and Kalm is given as authority for 

 its existence in Canada, where, by the way, it is never seen. The description is, 

 on the whole, good: "Maxillae apex simus triqueter," &c. Yet Linnaeus attributes 

 to this species the habits of another and an entirely distinct species, the Black 

 Snake, as derived from Kalm: "adoritur homines circum pedes sese convolvens," 

 &c., which the Coluber simus never does. Linnaeus here certainly confounded 

 two very dissimilar animals; and of this he himself was afterwards aware, for he 

 corrects the error in his twelfth edition, and gives excellent descriptions of both 

 these animals, the Hog Nose and the Black Snake: of the former (Heterodon 

 simus) he says, "Caput sub-rotundum, simum gibbum," &c., and to the latter 

 (Coluber constrictor) he properly enough gives the habits attributed to it by 

 Kalm, "Adoritur homines," &:c. 



The remarks of Cuvier on the Heterodon simus are curious; he says "Linnfcus 

 indicated this serpent in his tenth edition under the name Coluber constrictor, and 

 it is not known why in the twelfth he changed it to that of Boa contortrix."* 

 Linnaeus, it appears to me, never made the change supposed by Cuvier. The 

 Coluber constrictor of the tenth edition probably represented our animal, and 

 certainly disappears in the twelfth, and is replaced by two new species, the Hog 

 Nose and the Black Snake, and not by the Boa contortrix, for in the account of 

 this latter animal, Linnaeus does not preserve a single character of his original 

 Coluber constrictor, neither the "maxillae apex simus triqueter," nor the "adoritur 

 homines," &c. nor the number of plates — nor the same geographical distribution; 

 the one belongs to Canada, the other he received from South Carolina. The one 

 he considers an innocuous animal, the other as a poisonous one. "Sacculos 

 venenatos habet," &c. Why he should have given Catesby's Hog Nose as 



* Linnaeus avait bien indique ce serpent dans sa dixi^me edition sous le nom de Coluber 

 constrictor, on ne scait pourquoi il I'a change dans sa douzieme en Boa contortrix. — Regno 

 Animal, torn. ii. p. 82. 



