Title: The Day of the Brown Horde
Description: A 1929 American novel exhibiting <a href="https://en.wikipedia.org/wiki/Scientific_racism">scientific racism</a> and cultural obtuseness in its depiction of the savagery and violence in a fictional pre-historic society, described as <a href="https://en.wikipedia.org/wiki/Craniometry#Cranial_capacity,_races_and_19th%E2%80%9320th-century_scientific_ideas">brachycephalic</a> and with heavily-emphasized brown skin.  A 1944 re-print in the volume 6, № 2 September issue of the magazine *Famous Fantastic Mysteries* is <a href="https://archive.org/details/Famous_Fantastic_Mysteries_v06_n02_1944-09.Popular_cape1736_edit/page/n7/mode/2up">available at the Internet Archive</a>.
Subjects: craniometry, brachycephaly, scientific racism, evolution, cavemen, murder, homicide, infanticide, religion, American Science fiction
Time periods: pre-history