Many accounts are incomplete although new information is being added continuously.
Errors do occur.
Users are cautioned to refer back to the original cited source to assess completeness and correctness before using the information. Web updates are intermittent, not continuous, therefore some dynamic information such as legal status may not be absolutely current. If considered conspecific with E. tetragrammus, the overall range of the species would extend eastward to central Texas and southward to San Luis Potosi. In New Mexico, E.callicephalus occurs only in the southern Peloncillo Mountains of southwest Hidalgo County. It is known only from Geronimo Trail and Guadalup Canyon, where it is uncommon in its limited habitat.