Callophis, harmless mimicking poisonous species, 262.    From Wordnik.com.  [Darwinism (1889)] Reference

Callophis (belonging to the same family as the American Elaps) have large poison fangs, other species of the same genus have none; and that one of the latter (C. gracilis) resembles a poisonous species (C. intestinalis) so closely, that only an exact comparison will discover the difference of colour and marking.    From Wordnik.com.  [Darwinism (1889)] Reference