As I have mentioned numerous times, more than 95% (probably closer to 98%) of all Altemus published books were initially printed within a series. Sometimes I am quite sure a book is a series book but I cannot identify the series. Here is an example.

This edition of House of the Wolf was published in 1899. This is clear because the copyright on the picture is 1899 and the title page imprint is Henry Altemus which indicates a pre-1900 publication. The cover of this book is unlike any other series cover I have seen yet the size of the book (6.5 x 4.5), the title page and the title of the book are all indicative of an Altemus publisher’s series book.

Originally the book had either a dust jacket or a box which would have noted the name of the series. Until I find one of those elusive items, this cover will have to go into the unknown series section.

See http://henryaltemus.com/series/series-unknown.htm for other Unknown Series books.