Jerry G. Walls is an editor, author, and amateur conchologist who has described numerous species of marine and freshwater gastropods. Specializing in cones, cowries, conchs, and olives, he is best known for his 1979 publication Cone Shells: A Synopsis of the Living Conidae.
I've read through this book several times in my life. I had an African Black (Archispirostreptus gigas) before they became so expensive, and this was very helpful in many areas. Such as the mites. I had no idea if they were good or bad at the time. Very useful for millipede enthusiasts.