Fine-scan magnetograms and large-scale Ha filtergrams of an active region were made simultaneously. From the on-band pictures we could identify bright and dark fine mottles (<1600 km), coarse dark mottles ( 5000 km), bright and dark fibrils, and filaments. Small dark mottles have lifetimes of about 10 min, and large dark mottles have lifetimes of about 15 min. The lifetimes of bright fine mottles are much longer than those of the dark mottles. There are two clear-cut distinctions between dark fibrils and filaments. The fibrils show increased contrast when seen on the blue wing of Ha, while on the same filtergrams the contrast of the filaments decreases. The fibrils seem to lie perpendicular to isogauss lines of the longitudinal field measured in the photosphere, and the filaments in general lie parallel to these isogauss lines and over the null line of the field. It is evident that the filaments lie at higher layers than do the fibrils, and are different in nature. A ring of fibrils is found to occupy the position of the 15-G contour line (also the outline of the calcium plage). The calcium network pattern can be seen on the bluewing Ha filtergrams as regions of small plages surrounded by fibrils. We suggest that these fibrils are associated with spicules. In Ha movies it is evident that the portion of the chromosphere outside the 15-G contour lines is undergoing some type of random seething motion. Most of this (seen on-band) is actually a change in size and shape of the mottles. An important 1- flare occurred during the observations. No changes in the isogauss maps could be detected before and after the flare, but some slight changes in some chromospheric structures were noted.