OpenTwo archives, queried live.
Every record below comes from The Met or Smithsonian Open Access and was filtered on that archive’s own rights field before it reached this page. 12 shown for “Chamaesiphon ferrugineus F.E. Fritsch” — 40 records examined, 0 dropped by the rights gate.
Archives queried 2026-09-01 20:12 UTC · fetched live for this request
isPublicDomain field is true for this object.metadata_usage.access reads CC0 — a waiver, not an expired term.
Chamaesiphon ferrugineus F.E. Fritsch
Artist not stated in the record · 3 Sep 1918
Chamaesiphon pseudo-polymorphus F.E. Fritsch
Artist not stated in the record · 5 Sep 1920
Chamaesiphon fuscus var. auratus Hansg.
Artist not stated in the record · 1891
Xenococcus britannicus F.E. Fritsch in G.S. West & F.E. Fritsch
Artist not stated in the record · 2 Sep 1918
Chroococcopsis fluminensis F.E. Fritsch
Artist not stated in the record · 1 Sep 1920
Entophysalis rivularis (Kütz.) F.E. Drouet
Artist not stated in the record · -- Jul ----
Phormidium priestleyi F.E. Fritsch
Artist not stated in the record · 3 Sep 2013
Nostoc longstaffii F.E. Fritsch
Artist not stated in the record · Feb 1902
Oscillatoria simplicissima var. antarctica F.E. Fritsch
Artist not stated in the record · 2 Dec 1902
Lyngbya attenuata F.E. Fritsch
Artist not stated in the record · 2 Dec 1902
Microcystis parasitica var. glacialis F.E. Fritsch
Artist not stated in the record · 13 Sep 1902
Lyngbya scottii F.E. Fritsch
Artist not stated in the record · 20 Jan 1902
Where these records came from.
Two archives are wired, and only two. Each one is filtered on its own rights field — never on a title match, and never on the presence of an image file.
- The Met Collection API (Open Access)Rights field:
isPublicDomain. The archive returned no records for this term.0 matched - Smithsonian Open Access API (api.si.edu)Rights field:
content.descriptiveNonRepeating.metadata_usage.access. 5313 matched · 40 examined · 0 dropped by the rights gate. Kept only where metadata_usage.access === "CC0" and an image resource was published.12 shown
These figures describe the pass run at 2026-09-01 20:12 UTC, during this request. A completed pass is kept for 24 hours and replayed for an identical search, which is what keeps repeated queries inside Smithsonian’s 30-requests-per-hour allowance. A pass in which either archive failed to answer is never kept — an outage must not be replayed as though it were a finding about the catalogue.
Wikimedia Commons and the Library of Congress are deliberately not wired. Wikimedia was confirmed, on a live query, to return CC-BY material inside the same result set as genuine public domain works, and filtering it safely has not been designed yet. loc.gov was blocked by bot detection during the source evaluation, so its rights vocabulary has never been observed — and nothing here is built on a field nobody has read.
An image file is a rights claim. It never travels without its field.