60 HETERODON SIMUS. 
This serpent, it would seem, was first admitted into the tenth edition of the 
Systema Nature 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: “Maxille apex simus triqueter,” &c. Yet Linneus 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. Linneeus 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 “Linneus 
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.’* 
Linnxus, 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, Linneus does not preserve a single character of his original 
Coluber constrictor, neither the “maxille 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 
* Linneus avait bien indiqué ce serpent dans sa dixiéme édition sous le nom de Coluber 
constrictor, on ne scait pourquoi il l’a changé dans sa douziéme en Boa contortrix.—Regne 
Animal, tom. ii. p. 82. 
