This work is one of a number that comprised the phallic series, purportedly crafted by Hargrave Jennings anonymously to skirt censorship due to the taboo nature of the subject; it titillates the reader by rendering the solar, phallicist worship of the linga etc to degenerated status, then refusing to flesh out the more lurid parts of cultish ritual. Indeed the work isn't inaccurate...
This work is a bit more like "Archaic Rock Inscriptions" than it is the progenitor work "Phallism" albeit it is from the same series. Like other works within the phallism series (again, as always, possibly but not definitively a work by Jennings Hargrave) it relies predominantly on secondary sources, in this case mostly archaeological.