We used a Dynaphot Scanning Light Microscope (SLM), manufactured by Irvine Optical of California, to photograph all the species that we discuss. The SLM takes a composite photograph of the specimen as it moves through a lighted focal plane that has a bandwidth of 50-100 micrometers so that the photograph only records the sections that are lighted and in focus. Although new digital electronic cameras on microscopes allow a micrograph to be "assembled" from a group of photo "slices" pieced together electronically, with current technology electronic resolution is still much less than that of film and the image cannot be significantly enlarged without losing resolution.
The major limitation of the SLM is that the light bandwidth is sometimes more than the width of some smaller species. Another limitation, related to the light bandwidth, is the magnification obtainable with our system—its maximum is 40x—which is not sufficient for some of the smaller species, but it may explain why even with the smaller species we get good photographs. The images are in focus and can be enlarged photographically, so they are better than ones taken at higher magnifications with other photographic systems. Finally, from a technical point of view, the horizontal, narrow band lighting means that specimens must be mounted in such a way that the light will get into critical regions such as umbilical cavities. Some features are virtually impossible to light; hence, some photographs have dark areas that are unavoidable. Also, some of the angles of specimens are not the "standard" views that micropaleontologists are accustomed to with SEM photographs.
We used Fuji 64T® color slide film (35 mm) for the photographs. In some cases 10 x 10 cm sheet film might have been better, but it could not be used to produce a slide. We used slide film because with slides it is possible to enlarge them on a screen to whatever size necessary to examine them. The slides are reproduced here in plates 1-14 after being scanned into Adobe® Photoshop and electronically adjusted for contrast and brightness. These are second-generation reproductions; the originals are high resolution color slides that have a dpi of probably 5000-6000 (as opposed to the scan resolution of 720 dpi of the electronic scans). Copies of the original slides are available (see the Appendix for availability).