Apart from the morbid coincidence of dying in the same year–1895–there’s not a whole lot binding these two scientific luminaries together. Minerals and volcanoes on one hand and entomology and horticulture on the other. But, the world is small and the sub-world of scientific publishing even smaller, so onward, ho!
And as we all now know, Charles V. Riley (September 19, 1843 – September 14, 1895) studied botany and horticulture with sufficient vigor and savvy to help save the French wine industry from biological infestations of Phylloxera that threatened production. (click here for more detailed information, in case you missed it in earlier comments).
And, as it turns out, both figures published extensively in the American Journal of Science, but mentioning that sooner would have precluded the whirlwind tour of the collection that we all enjoyed so much!