The Actinopterygii /ˌæktɨnˌɒptəˈrɪdʒi.aɪ/, or ray-finned fishes, constitute a class or subclass of the bony fishes. The ray-finned fishes are so called because they possess lepidotrichia or "fin rays", their fins being webs of skin supported by bony or horny spines ("rays"), as opposed to the fleshy,lobed fins that characterize the class Sarcopterygii which also, however, possess lepidotrichia. These actinopterygianfin rays attach directly to the proximal or basal skeletal elements, the radials, which represent the link or connectionbetween these fins and the internal skeleton (e.g., pelvic and pectoral girdles).