Loose photographs in various size formats, including some in colour.

Where indicated photographs have been refiled from correspondence series for preservation reasons. The link back to original order has been maintained. Some ephemera has been included when it supports the reference back to the photograph's context.

People, places and research topics discussed:

1. Ritter collection. Stereobalanus canadensis willeyia SEO 1976 comprising 5 photographs 20x26 cm each annotated
   
   
2. Ritter collection. Stereobalanus willeyia comprising 38 photographs 20x26 cm each annotated