Animals called \ by Linnaeus, Amphibia . 3^ 
In the upper jaw, both of venomous Serpents and others, 
befides the teeth already fpoken of, there are two interior 
rows ; confequently, the diftindion I have endeavoured to 
eftabliffi might be expreifed in other words, by faying, that 
all venomous Serpents have only two rows of teeth, in the upper 
jaw, and all others have four I think it better, however, 
to leave the interior rows out of the queftion, as, in many 
fpecies, the teeth of which they are compofed are fo fmall, as 
to make it very difficult to difcover them. Indeed, in two 
fpecies of Anguis, I can hardly be fure that I have difcovered 
them ; but as, in every other fpecies, I have never failed to 
do fo, I prefume I may, with very little rifk of error, affert, 
that all Serpents whatever are furnifhed with them ; and that 
thofe only, which are not venomous, have the exterior rows. 
What I have faid fufficiently (hews that Linnaeus’s ideas, 
refpeding venomous ferpents, were fuch as did not permit 
him to feparate them from the others ; if the method I have 
propofed fhall be found to render the diftindion of them fuffi- 
ciently clear and eafy, it naturally follows, that they fhould be 
madegenericallydiftind. Some other reforms might alfo be made 
in Linnaeus’s clafs of Amphibia, the confideration of which 
I do not mean, at prefent, to enter further into. But, be- 
fore I conclude, I think it neceffary to notice an inaccuracy 
of Linnaeus, of a different kind from thofe I have already 
pointed out. 
* Gronovius, of whofe inaccuracy I have already given one Inftance, in 
defcribing the Crotalus Duriffus, in his Mufeum Ichthyologicum, fays it has no 
teeth, except the venomous fangs. Klein, in his Tentamen Herpetologbe, has' 
gone Hill further, having actually made a genus of Serpents without teeth, which 
he calls Anodon. He appears not to have examined the mouth of a linglc 
fpecies j but to have depended intirely upon the descriptions of Se e a. 
F a In 
