Dr. Engelmann on the Cereus giganteus of California. 5 
and even the free upper part of the ovary. In all the Cerei and 
Echinocacti examined by me, I find the lowest part of the tube 
free, the filaments being adnate to some distance above the ovary. 
It is not improbable that the Chilian velvety Cerei ( Velutini , Pr. 
Salm.) are to be classed near our species. The flower of what 
appears to be Cereus Cliilensis , Pfr., obtained near Valparaiso, and 
figured by the artist of the U. S. Exploring Expedition, greatly 
resembles that of C. Thurberi: it is a little larger, but has 
the same shape, and the same closely imbricated sepals on the 
ovary ; the tube has about 100 sepals, and the white petals are 
aeute : whether fleshy or not is uncertain. 
