Reptile & Amphibian Forums

Hi,

Not sure if I have ever seen this question adequately/definitively answered. Typically, infralabials are defined as "scales on the lower jaw below the lip and touching it." Supralabials are similarly defined: "scales on the upper jaw above the lip and touching it."

Seems simple, but have a look at (specifically pictures #11 and #12):

http://www.worldwidesnakes.com/ri-reptile-basic-anatomy-Scales.php

Reading various scientific & hobbyist literature, infralabial & supralabial counts correspond with images 11 & 12. Very rarely are the scales defined, but when they are, it is almost always as per the definitions written above. Thus, pictures 11 & 12 show 8 supralabials & 6 infralabials, respectively.

However, the definition of an infralabial scale & image 11 do not correspond! There should be up to 3 more infralabials in image 11. This is particularly annoying when using field guides and reading new species accounts.

Does anyone know the "correct" way to count infralabial scales? Literature &/or web links would be appreciated.

Thanks!

I'd add "enlarged" to those definitions. That would make infralabials the enlarged scales on the lower jaw below the lip and touching it.

If you look at the picture of the underside of the lower jaw, there is a pair of scales between the mental and gulars that seem to touch the lip. That would make 7 infralabials.

Generalizing from the number of mistakes on the genetics page, I'd not use that web site as an authoritative source.

>Does anyone know the "correct" way to count infralabial scales? Literature &/or web links would be appreciated.

James A. Peters, The Dictionary of Herpetology.
Conant and Collins, Field Guide to the Amphibians and Reptiles of the Eastern United States and Canada (Peterson Field Guide Series). Illustration inside the front cover.

Paul Hollander