Smooth Surface from Circles and Surface Below

Hoping to get some direction on how to execute an idea. I'd like to create a smooth surface that combines a number of circles and an underlying surface to get the visual effect of the underside of an octopus arm (if that makes sense). I've attached my grasshopper definition so far but I'm not sure where to go next to get the circles to transition smoothly into the the surface below. Looking forward to hearing some advice! Thanks!