Torei Enji enso
This enso is by Torei Enji (1721-1792), who excelled at the Zen circle. Torei began this one by pressing his brush down hard at the lower left and swiftly continuing around the circle while lifting the brush.
The calligraphy says “In heaven and on the earth, I alone am worthy of honor,” lines attributed at birth to the historical Buddha.
Yoko Woodson, curator of Japanese art at the Asian Art Museum, thinks that the curious smudgy echo of the enso at the lower left represents a shell.