The Stuart R. Stidolph Diatom Atlas
By Stuart R. Stidolph (images); Frithjof A.S. Sterrenburg (review and comments)
Introduction
This collection of LM images of marine diatoms, made in the Eighties and Nineties, epitomizes the craftsmanship of the analog era of photomicrography. What is presented here is the original version of the material, with the traditional species names, but amended where required.
Photomicrographic technique
All images were made with the following objectives: 20x/NA/0.70 and dry 40x/NA 0.95 planapochromatic, 90x/NA 1.4 apochromatic or a 60x/N.A. 1.4 planapochromatic oil immersion, combined with a 3.3x or 6.7x NFK photo eyepiece and enlarged to the magnification specified for the image in question. The film used was Kodak 2415 document film, developed in a slightly modified version of Kodak D19.
All images are unstacked - instead, images at different focus settings are presented in some cases. The photomicrographs were taken with conventional central brightfield illumination, phase-contrast or interference contrast were not used.
Magnifications
The legends mention magnifications for the various images. From these data, the optical combination used can be derived as follows:
90 x 6.7 = x2000 40 x 3.3 = x750
60 x 6.7 = x2000 20 x 6.7 = x500
40 x 6.7 = x1000 20 x 3.3 = x250
Scale bars have been added to the plates representing 100 mm at 1000x and the correspondingly scaled value for the other magnifications.
Identifications
Wherever possible Stidolph’s identifications were based on the illustrations supplied by the original author. If original data were unavailable, the reference source in closest agreement with the specimens was used.
In some cases, the identification was given by the maker of the slide, deposited in the collection mentioned. When Stidolph doubted this, a note was added. Where possible, this has been verified and commented upon where required. The references given originally are fully specified in a separate table, see further. The identifications given follow the “classic” system, where Lyrella species were assigned to the genus “Navicula”, for instance.
Materials
The materials are specified in the legends for the plates. Some were samples from which slides were made by Stidolph (deposited in the Stidolph collection, herbarium of the National Institute of Water and Atmospheric Research (NIWA), Wellington, N.Z.), others are slides by other makers, deposited in the collections specified. For the latter, all available information from the slide labels has been added.
The materials typically represent marine (sub)tropical habitats, the diatoms illustrated are typically inhabitants of the benthos or epipelic.
The atlas is available as pdf files, listed below, under the Creative Commons License.
- Azores 1: plate text
- Azores 2: plate text
- Azores 3: plate text
- Azores 4: plate text
- Azores 5: plate text
- Azores 6: plate text
- Azores 7: plate text
- Azores 8: plate text
- Rea Island, Singapore: plate text
- Cooktown, NE Australia: plate 1, plate 2, text
- Samarang, Java: plate 1, plate 2, text
- Indonesia: plate 1, plate 2, text
- Aberdeen Bay, Hongkong: plate 1, plate 2, text
- Muntok, Singapore: plate 1, plate 2, text
- New Hebrides: plate 1, plate 2, text
- King George Sound, Australia: plate 1, plate 2, plate 3, text
- Campeche Bay: plate 1, plate 2, plate 3, plate 4, plate 5, text
- Cape Verde: plate 1, plate 2, plate 3, plate 4, plate 5, text
- Samoa: plate 1, plate 2, plate 3, plate 4, plate 5, text
- Philippines: plate 1, plate 2, plate 3, plate 4, plate 5, text
- Galapagos: plate 1, plate 2, plate 3, plate 4, plate 5, plate 6, plate 7, text
- Various and unknown localities: plate 1, plate 2, plate 3, text
- ...