Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Cydnidae of the Western Hemisphere
By Froeschner, R. C.
Proceedings of the United States National Museum, 111(3430): 337-680, 13 plates., 1960
Cite: 548422 with citation markup [cite:548422]
Full text available here. (Large file-size, very bad scan quality of the plates)

BHL version with better quality: https://www.biodiversitylibrary.org/part/38481

superb treatment, illustrations are just fantastic
too bad they didn't come up well in the online PDF file (the original drawings are too subtle, with lines thinner than hair)
i think we could figure out a few submissions sitting at the subfam. level using this monograph

 
it is great
If you ever come across a cleaner version, let me know. Maybe some kind soul will rescan the plates. On a side note, I was able to track down a copy of McAtee & Malloch's revision of Thyreocorinae; I hope to scan it when I have a chance.