Online there is this image of a lamellar structure which is, I suppose, in the alveolus of some species.  The labels in this publication are not that clear. The author data are: Pulmonary alveolar proteinosis. R. Borie, C. Danel, M-P. Debray, C. Taille, M-C. Dombret, M. Aubier, R. Epaud, B. Crestani European Respiratory Review 2011 20: 98-107; DOI: 10.1183/09059180.00001311, but they reference someone else for producing this micorgraph, but that reference did not show up any images such as this.  So, it is unfortunate because no species, treatment, magnification or other descriptors are provided for this protein-lipid-whorl structure, and it does have the two dense line – central dotted line that the RER profiles in some of the alveolar type II cells posted on this blog, in search of the identity of the protein in those profiles.  It would have been great to know the magnification, and hence the number of nm between the two dense lines of this lamellated alveolar structure.  (used without permission, but credit is given as far as i can determine). Blue arrows point to the central line (inset is from upper left-middle of the lower mag image) and red arrows point to the outer dense lines.  It is too bad I don’t have a micron marker for this image.