Mus., 1893-1896) accepted Cope's principles, and mainly by .combining the Asinea of Stannius and Cope with the Proteroglypha as Colubridae - wherein he was followed by Cope, as mentioned above - and separating therefrom the Peropoda or Boidae, he has produced a logically-conceived system, by far the best hitherto proposed.
Ilysiidae Xenopeltidae Colubridae Aglypha Typhlopidae Boidae Glauconiidae 'This means that the Boidae retain most primitive characters.
The solitary Xenopeltis is in several ways intermediate between Boidae and Ilysiidae.
The Boidae comprise some 60 species, which have been grouped into many fancy genera.
Boulenger rightly considers this snake in various ways intermediate between the Ilysiidae, Boidae and Colubridae.